FF only removed the SSB (site specific browser) feature on desktop which was in an alpha state. There was no announcement that Mozilla was going to remove the entire PWA features (such as service workers).

PWA is a set of modern web standards. "Supporting PWA" can mean many things but "Removing unfinished SSB" doesn't mean "Removing PWA".

Unfortunately, the pendulum is also swinging away from Firefox.

Only for desktop, I think.