Let me propose that we no longer depend on chrome-gnome-shell at all from either 'gnome' or 'gnome-core'.
That leaves gnome-shell's Recommends on chrome-gnome-shell. We could demote it to a Suggests, but as long as GNOME supports the https://extensions.gnome.org/ service, it is a courtesy to our users to have that service work out of the box. Enrico, by the way, Simon McVittie points out that you are welcome to uninstall 'gnome-core' and just install gnome-session directly if you want a more minimal GNOME install than the one the Debian GNOME team recommends for most users. Thanks, Jeremy Bicha