WordPress having official SQLite support will make it more portable and self-contained for hosting on edge platforms, as well as in the browser via WebAssembly.

That is exactly what we are working on at WasmLabs! https://wordpress.wasmlabs.dev

After the article about running WordPress in the browser was published, there's a new project called WordPress Playground which is gradually preparing NPM or Composer packages to make it easier for people to run it.

https://github.com/WordPress/wordpress-playground/

They've been doing very detailed work, like making some patches to PHP and SQLite for improved compatibility with Emscripten, etc. It seems there's a lot of overlap with what WasmLabs has achieved and probably have continued to develop further. Perhaps there's an opportunity for collaboration.