It is known since this age verification has existed for a while now in some regions, it’s only now rolling out globally.
The server owner is the one that marks a server or specific channels as NSFW.
So if you don’t send/visw anything NSFW this won’t impact you.
It’s already implemented. Tons of users have already scanned their faces/IDs to prove their identity/age. This is just a global rollout.
If you don’t do problematic things you won’t be seen as the problem. The vast majority of tourists aren’t doing anything bad either.
The issue is that there are so, so many tourists coming to Japan that even if only 0.1% of them are bad, that’s still tens of thousands of people, which ends up leaving a dent in absolute numbers regardless.
It’s a hard problem to manage because there will always be a small amount of people misbehaving no matter where in the world you go.
In fact, knowing that the only thing Proton was able to hand over was the credit card identifier is pretty solid proof that they in fact cannot access (and thus provide access to) your email account and its contents.
If full anonimity is the goal then stick to crypto or cash payments, because credit card always leaves a trail and not a single email provider is above the law in that regard.
This case is entirely the fault of the user’s bad opsec.