Any and all coins are at risk of being flagged by centralized exchanges. Centralized exchanges use different blockchain analysis services which have different criteria and different blacklists for which coins they will and will not accept. What is acceptable to one exchange may not be acceptable to another, and vice versa. I
previously did a quick analysis which showed one particular blockchain analysis service thought that 25% of the coins coming out of Binance should be blacklisted. You could quite easily buy all your coins through a regulated KYC exchange and find them seized when you deposit them to another regulated KYC exchange. Never mind all the other risks which come with using KYC exchanges of zero privacy, zero security, the possibility of scams, insolvencies, hacks, data leaks, etc., and the possibility the government shutdown or seize all their assets at any time.
This is pretty scary! To suddenly lose one's coins to seizure by an over-zealous exchange simply due to the history of those coins.
With centralized exchanges, you can never know what else has changed in their rules, why, as o_e_l_e_o correctly wrote, they can suddenly declare "dirty" even bitcoins bought on another centralized exchange. And at the same time, they often say that they do not disclose their algorithms for determining problematic transactions. That is, when interacting with a centralized exchange, you have to completely rely on the fact that it will not deceive you. All funds transferred to it instantly end up in its full and undivided power.
And you correctly write in the first post that they will transfer all your KYC data on the first request to anyone, not to mention how many leaks of critical data from exchanges occur. And the fact that you potentially become a convenient suspect, even if you later manage to prove your innocence, will lead to a waste of time and nerves.
The less we interact with centralized exchanges, the better, in my opinion. And we should never go through KYC for bitcoins at all.