IMO, the Mobo will support a Max OC of upto 2000MHz for the RAM. Withe a standard RAM of max OC 2000MHz, the user would have OCe'd everything to get to that speed, for all we know he would have even bumped up the voltage to 1.65V to maintain that speed. If he was successful in the feat, then he'd sure have reached that point of stability going through a few BSODs, changing a few timings here and there, multipliers up and down, etc etc.
Scenario changes, we have a RAM of Higher OC capabilities at the same Voltages, timings changed, now the rig is automatically going to downclock it to 1333, first.
And the journey begins again....... only difference is, the RAM is going to be working at a frequency that is not specified to the brackets that we are used to, making it a little more troublesome adjusting. It is not going to downclock the RAM straight to 2000MHz for the OP. That's the whole way it might go, but, it's my opinion, that for someone who's new to the business, it's better not to risk the $$ on stuff that might lead to greater headaches.