You guess wrongly. It takes a lot more than a quick patch to enable DX12. If at the time when they built the engine they didn't have access to the new API, it means they would have to rebuild the engine to some extent for it to take advantage of DX12.
Granted, they MAY have been hard at work on updating the game engine for DX12 in the last year since DX12 was revealed by Microsoft and they may have plans to update the game for it, but I wouldn't count on it.
"In patch 1.07, the level requirements for certain items were scaled up, leaving some players stuck with only unusable gear. With patch 1.08, we are introducing the Wolven Hour potion. This potion will be available in everyone's inventory once they install the patch. It will reduce level requirements on all gear for a period of one hour. This will give players time to level up or find alternative equipment using the gear that was available to them in patch 1.05 but became unusable after patch 1.07. After one hour, the potion's effects will cease and the requirements for all gear will revert to their original, pre-potion values."
CDPR could have just said "deal with it" and moved on, and the fact that they didn't strikes me as worthy of special recognition.