The Bitwarden Flatpak which has been unofficially available on Flathub for some time, has recently been relisted as verified / official.
I haven’t seen an announcement yet from Bitwarden, but Flathub now lists it as official/verified, and there was a commit 4 days ago which removed the ‘unofficial’ warning.
Side Note (on other possibly positive flatpak news)
ProtonVPN’s small Linux team has grown from 1 to 3, and has also recently expressed possible intent (but no guarantee) of taking over the (currently unofficial) ProtonVPN flatpak. See here