KptMarchewa parent
I would guess AML, not fraud.
I think they're saying there's an inherent ponzenomics to payment processing, wherein the might use AML as an excuse to paper over a lack of liquidity by stalling withdrawals. Lots of cryptoasset exchanges will freeze withdrawals over fictitious security or AML concerns when they're going under, for instance.
AML regulations are real, though. Crypto exchanges' fictitious claims wouldn't fool anybody if it wasn't already "a thing" in the more-regulated side of the world.
I haven't seen real example of this in real money financial institutions. Haven't followed crypto exchanges though.
I'll add that I'm also not aware of something like this happening outside of crypto exchanges & don't actually hold an opinion on this hypothesis, as I'm not familiar enough with payment processors to know one way or the other. My comment makes me sound like I support this hypothesis, but that's a mistake in my wording.