This reminds me of when leadership announces a policy over email. Sure, all the people who got the email can follow it, but what about people who join the team in the future? Either they find out about the policy when they violate it and get reprimanded, or they hear about it via word of mouth.
For sure! Why can't it be "we have updated/created X policy, please find it here: <link to document in policy repository>" ? Is that so much harder?
Most document management systems have a notification system built-in so that you can automatically email your all-staff mailing list when there is an update. It's very much a solved problem.
I've seen it a number of times in my career.