"+ libappindicator (external dependency)
- it doesn't integrate with gnome-shell
- probably depends on GtkApplication, and would need integration in
- we wished there was some constructive discussion around it, pushed
by the libappindicator developers; but it didn't happen.
- there's nothing in GNOME needing it.
=> rejected for the reasons stated above"
Basically Ubuntu it just hoping that things get accepted without working closely enough with the GNOME community to make this happen. That's really unfortunate as everybody would love to work together with them more closely. That would mean that they would have to release things early and not just send an announcement when things are set in stone.