Restore Online Accounts page
The GNOME Online Accounts (GOA) page of Initial Setup was removed because the GOA workflow seemed incompatible with Initial Setup's New User mode. See #202 (closed)
However Debian and Ubuntu also use the Existing User mode (which admittedly is disabled in GNOME itself) as a more featureful alternative to GNOME Tour. In Existing User mode, the GOA links to the user's web browser might not be that much more disruptive than the corresponding GOA links in GNOME Settings.
I think there was some interest in Fedora in using Initial Setup beyond New User mode too. (See !200 which I believe Fedora carries downstream.)
Notably, it is easily possible to have different pages in new user mode than in existing user mode.
cc/ @mcatanzaro