IRS doesn’t care as long as you pay taxes on the money.
KYC and AML? Just lie that you mined the monero on a now defunct pool. I have a plenty of coins that I genuinely acquired in such manner and haven’t had issues selling them. The bank only cares about hearing a vaguely consistent story, they aren’t cops.
The KYC stuff will only become a problem if you get caught via some other means, because lying to the bank is a crime.