Yikes! good luck, hope it works out. This is scary. Gmail is still, by far, the best email app. Something like this could happen to me and, I suspect, a lot of other people.
These ToS, CSAM, moderation, etc are very orthogonal to the app itself. Why conflate them? Most non-hackernews people are completely unaware of them, so it won't be a factor in their choice of platform. Are we even sure other apps aren't doing similar things? Or have equally dangerous practices around password changes?
But switching to Fastmail, I no longer agree that it is "by far" the best. Now I think Gmail is only better by a slight margin, and this margin is so small that it does not justify the drawbacks: Potentially getting locked out with no recourse, certainly getting everything you receive scanned to deliver you the best possible ads, contribute to the email monopoly where the big players decide the protocols.
I know it seems lo-tech, but it's a good idea to print out the ten Gmail recovery codes and keep them in a safe place. I've done the same for GitHub too.
I find this opinion absurd. It is an e-mail client. Even if it did perform the tasks that an e-mail client needs to perform somewhat better than all other clients, the loss of autonomy makes it a terrible deal, even for non-technical users.