Is this related to web2js[1], which has been around for a while? It compiles the pascal code of TeX to wasm.

It looks like the live demo is no longer up, but it did run latex in the browser and render the dvi output to html. The wasm for TeX is about 495kb / 88kb compressed, but the memory image for LaTeX was a bit larger.

[1]: https://github.com/kisonecat/web2js