Here are the facts https://support.google.com/chrome/answer/7440301 Yes they still record your activity under some faceless uuid when you browse incognito. No they don't tie it with your gmail unless you login to gmail. Yes, it doesn't matter, since lawyers and government can access everything Google has, and put the pieces together. Policy will likely change in the future to make your full history of both gmail and anonymous browsing activity freely available to the public too.
Of course it's going to happen. Read The New Digital Age by Eric Schmidt. He talks a lot about how all the information Google records about you is permanent, can never be deleted, and any generation of lawmakers can decide to do whatever they want with it. Upcoming generations are going to want as much data as possible to train AIs, especially as the GPUs needed to do that become more affordable. You know how historians are always talking about what famous dead people wrote in their diaries and personal letters? Don't think for a moment that future generations won't do this to you.
