There's a delay in switching the flatpak to 140, since unlike the direct download, there's no way to slowly roll out the release to flatpak users. Once we switch to 140 on flatpak, everyone gets switched. This gives us a chance to make sure everything's working as it should, and it also gives add-on developers more time to upgrade, so flatpak users have more add-ons that work after the switch. Hope this makes sense - and we'll see if we can get an ETA.