WebAssembly as a technology is very interesting especially for embedded and headless IoT devices. The device may sit silent / dormant until contacted by a remote device (typically Android phone or a tablet, or a PC) running a standard browser.
It must be possible to build an embedded device that can deploy to a WebAssembly compliant remote browser.
The work under QTBUG-70806 should reveal what is in fact needed. Possibly new implementation in Qt Creator on how targetting devices will happen, or only documentation.