Did I just get defrauded by Coinbase?
No, you were not defrauded because you did not lose anything real.


You did not lose 10 BTC.
You did not lose $1,556.76.
You lost potential, yet unrealized gain as a result of the delay in processing your order.


You may have not had access to either amount for a period of time because of the flag thrown on your transaction.

AFAIK, Coinbase does not publish its criteria for flagging transactions. Doing so would likely make it more difficult to detect transactions that would defraud them. 

One way to look at it is that this is not Coinbase's fault. Coinbase has to protect itself from both financial and legal liability. It can refuse to do business with anyone it so desires if it feels the transaction may not be made with legally obtained funds by people with whom it can legally conduct business.

If you are unhappy with the delay, and that's enough of a transgression for you not to use Coinbase again, then that's your decision to make. However, this can happen with anyone as automated and needfully paranoid as Coinbase.