FB can't win this cat and mouse game. If the ads are to be distinguishable then there will be inherent properties that will lead to them getting blocked.
I think you're making some assumptions here. The logical end-game is that FB writes their own rendering engine in javascript and targets a single canvas element, handling all the interaction events themselves. In fact, I think it can go significantly further than that. Ad blockers will need to get much fancier to deal with that kind of weaponized ad delivery.
But also, adblockers will keep up. If they have to use canned deep-learning neural nets to catch and crush advertising based on how it looks rendered, they will.