These kinds of things have more to do with your bank than with Coinbase.
No it doesn't, Coinbase replied that it has to do with their algorithm. I have sold bitcoin and transferred the fiat back to my bank account many many times, but lately most of the sell bitcoin and transfer to bank account get cancelled.
Instead of going on some message board and smearing feces all over the walls making accusations and innuendo, then why not get in contact them and clear it up, because there has to be a reason you're getting flagged as high risk.