Likely the only reason Groups is still around is that if you want a mailing list on GSuite then this is your only option. If they kill it, many orgs will probably switch to Office 365 or another competitor the next day.
Google uses Groups internally and externally for all its mailing lists. It will never, ever die for that reason alone.
Honestly, this is the only proof I'm willing to accept for the survival of any low-revenue service that Google provides! But still, google code didn't live.
Google wasn't using Google Code.
Perhaps they meant Google Code Search?
Yeah, Code Search is a counterexample because Google was using it, but killed the public version to focus on internal use. Though it is still available to the public in limited form for Google's major open source projects as https://source.chromium.org/ and https://cs.android.com/