It's not just Treantmonk in this video?
No. But if he is in the video, I know it is about optimizing.
I am sure he will find good synergies when the rules are layid out in full.
To be fair, he even finds good synergies in classes and subclasses that are widely seen as underpowered.
He still does in no way represent the majotity of players. I think most of his assessments fair, but far away from the reality at my tables.
Treantmonk even admits, that the old ability had a loophole to get sneak attack twice.
I am also pretty sure, they have not yet seen the change to two weapon fighting. At least they don't mention it as a buff for the rogue.
I share their assessment with the thief.
I also share Treantmonks opinion, that sneak attack could be buffed a little to compensate for the loss of a second potential sneak attack.
Most funninly: In 4e it went from 1/round in O4E to 1/turn in essential.
So I am still totally divided. I still believe, sneak attack should work on your attack action, and not on a Magic action. But it could be spelled out, that it specifically works on opportunity attacks.