Yes he says to use a language that compiles to WASM for the UI parts to draw pixels on the screen.
It really seems like WASM will be the write once run everywhere runtime that was touted in the past. Java almost got us there but was too dependent on Java, whereas WASM is for any language. I've been using Flutter with their experimental web WASM support and it's very fast.
I hope it doesn't replace the lowest common denominator of HTML for generic apps, though, if only because it would dramatically raise the barrier to entry (not that your typical React app is particularly readable in the inspector...).
I personally use Flutter for a lot of my apps, as well as React/NextJS for SEO based apps, the combo works pretty well.
Whelps. Time to learn C++ again!
What does he suggest we do about the UI layer? Draw pixels on a canvas from WASM?