I hope your funds weren't in there (in fact never ever leave your valuable assets in any exchange in case you are going to be off trading for a long time)
These crypto exchanges are like unstable weather, you never know what kind of requirements or regulations they can come up with tomorrow.
The personalised links could have been tailored for the territory you come from since different territories have slightly different regulations.
A few months ago I removed most of my funds which might have triggered something. I have been a verified user for several years though.
I don't see many users getting the emails asking for the source of funds though so I guess my account is fine. I don't see any reason to panic if they ask for the source but I'd like to know if a lot of us received the email and goes on without worries after submitting documents. I checked my email which I find nothing is sent to me about it.
I have not logged to my account for a year but I have few tokens I kept like ADA but nothing much.
Check the document for the source of funds, it'd be impossible for me to even provide the documentation asked as some of the platforms I've traded on don't exist any longer.
Do you think it's normal one would need to provide bank statements showing employment income on demand of an exchange? Or retirement income receipts?
Luckily I caught it in time to remove my remaining assets.