You're misunderstanding a few things about those leaflets (which isn't entirely your fault, that page is very poorly written).
My understanding is that the "LeMay leaflets" were dropped on Hiroshima - and many other cities - but they didn't say anything specific about the bomb; just that America was bombing cities and encouraging civilians to flee. But, as we know (and they knew), America was already bombing Japanese cities - there wasn't any indication anything "special" was coming. The pamphlets actually excluded Hiroshima from the list of cities that might be bombed (with the caveat that the list was incomplete). Civilians were on edge, but often couldn't leave for various reasons, trusted things like air raid sirens, believed that their distance from military targets kept them relatively free from danger, and so on. This is documented in the essential "Hiroshima" article by John Hersey.
And these warnings weren't entirely ignored - Hiroshima's population before the bombing was substantially smaller than it was before the war, in large part because many Japanese civilians who could had fled cities.
The "Hiroshima pamphlet" - the one depicted - was not dropped on Hiroshima. This is apparent if you read the text, which describes Hiroshima as already destroyed; or the fact that it shows an image of the explosion over Hiroshima, not the Trinity test.
This [0] Reddit link - which I found by googling about the LeMay pamphlets - goes further to claim (and support, in the links) that even those weren't dropped over Hiroshima or Nagasaki. IIRC this contradicts Hersey's reporting, FWIW.
(Incidentally, based on the username, that Reddit comment was probably written by someone cited in your link. Either that or it's an eerie coincidence.)
I'm not sure what in my comment you're specifically referring to, but...sure, I'll bite.
Let's split hairs. The Tokyo firebombings killed, per Wikipedia, 80K-130K civilians, depending on your estimate. Again per Wikipedia, Little Boy killed 70K-126K civilians, as well as an additional 7K-20K soldiers and 12 American POWs. Given those numbers, rather than "more deadly" I'd prefer to say "just as deadly".
You're far from the only one in this comment thread to do this, but...I don't understand why the fact that the firebombing of Tokyo was approximately just as deadly as Hiroshima is supposed to somehow absolve Hiroshima. Most people who think Hiroshima was a war crime also think Tokyo was a war crime. The way I prefer to approach moral analysis, personally, isn't especially utilitarian - once we start splitting hairs about which war crime was more or less moral I can't help but feel like we might've lost the plot.
Now, with that aside, we can play some games here. Tokyo was (and is) a city an order of magnitude bigger than Hiroshima; 100,000 dead in Tokyo vs. 100,000 dead in Hiroshima means, in a sense, the attack on Tokyo was an order of magnitude less vicious. Maybe "viciousness" of an attack isn't especially meaningful on its own - if the US bombed the middle of nowhere to make a point and only a handful of people died it definitely wouldn't be as evil, even if the strength of the attack was the same. But this did have practical consequences - the infrastructure of Hiroshima to deal with the situation was demolished utterly. This meant no health care or support for any survivors - supposedly exactly one doctor was left uninjured. People were just left to suffer for days. In Tokyo there was still some health care available, there were still some support networks; because the destruction - awful as it was - was so much less complete, there was a much better chance that survivors could lean on friends or family for support. So the suffering of the survivors in Hiroshima was much greater. In this awful utilitarian Olympics of evil, the atom bomb takes a point.
There is, of course, the issue of radiation sickness. We do intuitively feel that, regardless of the particular numbers involved, chemical or biological warfare is a red line that musn't be crossed. It's one thing to blow people up, it's another thing to poison them - or give children cancer, as the case may be. Truman himself felt that way - although the scientists at Los Alamos had some idea about radiation Truman didn't, and some believe he might not have approved using the atom bomb if he'd known [0]. In that light, Hiroshima was definitively less moral than the firebombings.
And I guess it's worth stating that the truly deadly firebombing of Tokyo, Operation Meetinghouse, didn't come out of nowhere. The US had been bombing Japanese cities for three years. Operation Meetinghouse wasn't a surprise; it wasn't the first bombing of a Japanese city, it wasn't the first firebombing (that was in Kobe), it wasn't even the first firebombing of Tokyo (which happened a month prior). Since my argument here has been primarily "the US should have given the Japanese an understanding of their capabilities and given them an opportunity to surrender in light of them", I think you can make the case that they had with Tokyo in a way that they hadn't with Hiroshima, and that - at least by my own standards - that makes Hiroshima far more morally problematic.
I’m more wondering aloud whether the option to surrender is just tacitly always on the table during war.
If the allies had said ‘we will firebomb Hiroshima unless you surrender’ it might almost seem like a meaningless endeavor since it’s hard to draw the line when you should alert your enemy of your next military action since ‘surrender’ is (probably) always tacitly assumed an option.
In this sense, giving an enemy an option to surrender (again) seems moot on the moral framework of ‘we are at war and will continue to bomb until the enemy officially surrenders, since we both know it is always an option.’
My understanding is that the "LeMay leaflets" were dropped on Hiroshima - and many other cities - but they didn't say anything specific about the bomb; just that America was bombing cities and encouraging civilians to flee. But, as we know (and they knew), America was already bombing Japanese cities - there wasn't any indication anything "special" was coming. The pamphlets actually excluded Hiroshima from the list of cities that might be bombed (with the caveat that the list was incomplete). Civilians were on edge, but often couldn't leave for various reasons, trusted things like air raid sirens, believed that their distance from military targets kept them relatively free from danger, and so on. This is documented in the essential "Hiroshima" article by John Hersey.
And these warnings weren't entirely ignored - Hiroshima's population before the bombing was substantially smaller than it was before the war, in large part because many Japanese civilians who could had fled cities.
The "Hiroshima pamphlet" - the one depicted - was not dropped on Hiroshima. This is apparent if you read the text, which describes Hiroshima as already destroyed; or the fact that it shows an image of the explosion over Hiroshima, not the Trinity test.
This [0] Reddit link - which I found by googling about the LeMay pamphlets - goes further to claim (and support, in the links) that even those weren't dropped over Hiroshima or Nagasaki. IIRC this contradicts Hersey's reporting, FWIW.
(Incidentally, based on the username, that Reddit comment was probably written by someone cited in your link. Either that or it's an eerie coincidence.)
[0] https://www.reddit.com/r/AskHistorians/comments/8rgyky/comme...