The updated store policy explicitly allows Gecko browser engine.

Moreover, we don't have to convert the installer to a packaged app anymore.

Yeah, I brought that up in this bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=1549103#c4

I would really like to see it happen!

(In reply to Masatoshi Kimura [:emk] from comment #0)

The updated store policy explicitly allows Gecko browser engine.

Moreover, we don't have to convert the installer to a packaged app anymore.

Your wish has been granted: https://www.microsoft.com/store/productId/9NZVDKPMR9RD

Mozilla says that it'll become "available" by version 94: https://blog.mozilla.org/mozilla/news/news-from-firefox-focus-and-firefox-on-mobile/

This bug report should either be closed or merged with the one that Talam posted above. It is a duplicate.

This bug is about unpackaged Firefox app. Bug 1549103 is about MSIX packaged Firefox app.
I would like to leave this bug open because some bugs (such as bug 1736742) may be unresolvable as long as we use MSIX package.