[Supabase engineer & author of the blog post]
You can already use WASM modules within Edge Functions. We have an example on using WASM modules to generate OpenGraph images - https://github.com/supabase/supabase/tree/master/examples/ed...
We are also exploring ways to create functions in WASM-supported languages and run them directly on Edge Runtime. We expect this would be easier WasmGC[0] is shipped and Deno's WASI support improves.