You're suggesting this likely happens because the payment processor has reported their suspicions to a regulator who isn't getting back to them in a timely manner, and so they can't release the funds until they do? I'm a bit confused because it seems to me that the tip off is when they won't disburse your funds.

ETA: Maybe it's more that they can't give you any information because they can't allow adversaries to differentiate between glitches, random screenings, and investigations?