It's a shame that Yann didn't explicitly say what the misunderstanding was or clear it up.

I think he's claiming that the misunderstanding is that SORA understands the physical world. He goes on to say that generating the next frame conditional on some action is much harder than generating an entire plausible video. This just doesn't make sense to me. Every frame in a plausible video clearly needs to be conditioned on the actions shown in previous frames.

The tweet is mostly incoherent and I'm left assuming he's upset about SORA and wants to say his ideas are/were better but hasn't managed to express why in a meaningful way.