FWIW I have snap permissions visible in gnome-control-center aka “Settings”. The UI is very similar to Flatseal. It seems to match the command-line output apart from “content” entries, as well as “unity7”, “wayland” and “x11” (redundant info?).
I don’t know why Bitwarden needs audio permissions 
CLI output
$ snap connections bitwarden
Interface Plug Slot Notes
audio-playback bitwarden:audio-playback :audio-playback -
browser-support bitwarden:browser-support :browser-support -
content[gnome-3-28-1804] bitwarden:gnome-3-28-1804 gnome-3-28-1804:gnome-3-28-1804 -
content[gtk-3-themes] bitwarden:gtk-3-themes gtk-common-themes:gtk-3-themes -
content[icon-themes] bitwarden:icon-themes gtk-common-themes:icon-themes -
content[sound-themes] bitwarden:sound-themes gtk-common-themes:sound-themes -
desktop bitwarden:desktop :desktop -
desktop-legacy bitwarden:desktop-legacy :desktop-legacy -
gsettings bitwarden:gsettings :gsettings -
home bitwarden:home :home -
network bitwarden:network :network -
opengl bitwarden:opengl :opengl -
password-manager-service bitwarden:password-manager-service :password-manager-service manual
pulseaudio bitwarden:pulseaudio :pulseaudio -
unity7 bitwarden:unity7 :unity7 -
wayland bitwarden:wayland :wayland -
x11 bitwarden:x11 :x11 -
Screenshot
