[heavyset_go]

Firefox devs have confirmed that they'll implement Mv3, but without all of its restrictions and with compatibility for older extensions.

[iggldiggl]

While the capability of blocking web requests isn't in question, there are some rumblings around deprecating background pages in Firefox, too: https://bugzilla.mozilla.org/show_bug.cgi?id=1578286

Certainly nothing firm as far as it looks, but at the very least they're thinking about it, even though that change is somewhat problematic, too.