Most of the ones you named are Android based anyway except Sailfish OS and Ubuntu Touch.
As far as I understand Chrome OS will turn into Android, not vice versa.
Last I checked (in the last few months), GOS maintainer(s) were unsure if some proposed changes might kill the project in the near future, and I’m pretty sure that was unrelated to this announcement.
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Most of the ones you named are Android based anyway except Sailfish OS and Ubuntu Touch. As far as I understand Chrome OS will turn into Android, not vice versa.
So GrapheneOS is still the best bet.
Last I checked (in the last few months), GOS maintainer(s) were unsure if some proposed changes might kill the project in the near future, and I’m pretty sure that was unrelated to this announcement.