View attachment 288726
They mention specifically "US Social Security Number" meaning most probably it's going to be inside of US only, at least at first. No clue why other people say it is going to affect all countries.
Regarding which suspension, I guess every suspension type, including suspicious payments, and except for unauthorized access. Google doesn't mention it anywhere so you will only be able to find that out in a week, when, according to their message, they roll out this process on 10th of October.
I wonder if verifying an account increases the possibilities of its unsuspension.