As @iwalker says, Microsoft owns github so it’s not surprising if Google wants to owns a competitor.
I do not think it’s more likely that Google will close the community edition than GitLab (the current company, that is also - very clearly - in it to make money) doing it. But the code behind the community edition is open source, so Google can’t (legally) remove that from existence and I hope that someone will step up and maintain a fork if it is announced that only the enterprise edition will be developed going forward.
But self-hosting requires that there is something to host.
There are already devices that operate (almost) like appliances that support installing/running GitLab, their sales might increase if people start having to host their own.