Firefox 68.0
This marks the last Android release with extensions/add-on support.  There will not be a 69 release of this edition of Firefox for Android ("Fennec").The new remake of the mobile browser ("Fenix") does not have extensions support and it is on an indefinite and easily ignorable backlog.  It is explicitly not being worked on this quarter.  At the end of this quarter is the scheduled release of Firefox 69.  Unless there's no release at all of Firefox 69 upon the Android platform, that's the time when Mozilla I think will deceptively try to drop support for extensions/addons on android.Bug to have Add-ons pages declare Fenix extensions as unsupported.
"version <= 68.0.98 is legacy Fennec
version >= 68.0.99 is Fenix (or some other GeckoView-powered browser)"
https://bugzilla.mozilla.org/show_bug.cgi?id=1548428"Or do nothing because Fennec 68 and Fenix 68 will overlap for only 6–8 weeks with a preview audience."
https://github.com/mozilla/addons-frontend/issues/7963Firefox 69 releases 2019-09-03 at the end of Quarter 3.
https://wiki.mozilla.org/Release_Management/CalendarExtensions support are in the "Reserved Backlog" category. Also locked to prevent any more comments about it.
https://github.com/mozilla-mobile/fenix/issues/574Extensions support is not in Q3 backlog
https://github.com/mozilla-mobile/fenix/projects/19