They jumped the gun a bit with the page, but what I have been able to piece together so far is that they renamed the WASM runtime from Lumen to FireFly and FireFly is what powers this through WASM.

So OTP is running natively on the phone.

This is essentially React Native reinvented with Elixir, which to me is pretty awesome because I really dislike React Native although we have done quite a few projects with it :)

Edit: Totally mistaken, I stand corrected! Turns out I jumped the gun instead. Hopefully FireFly and this CAN give me the RN replacement I desire.