It's a clever idea/claim to make from a rhetorical stand point. Politically it sort of squeezes out the last bit of small block juice.
I don't think there is a precendent for his specific claim, as the up to now the main justification has been that larger blocks will centralize. It's an outright linguistic salvo (goal post shifting) and technical red line that favors the Blockstream mafia.
It's meme worthy, a short pithy idea toxics can rally behind if it gets confirmed by the usual suspects or otherwise amplified.