I found a guru3d thread about a driver modder http://forums.guru3d.com/showthread.php?t=379516

Its meant for enabling support for legacy cards on new drivers, but maybe it can enable new card support on old drivers too.

Tomorrow when I get home I'm going to try to mod the Novemeber AMD driver to work with the RX 570. In the meantime feel free to try it yourself.

PS: Device ID for RX 570 and 580 was already in drivers since November