While Google is notorious for rugpulling free services, I've not seen any such notification or news coverage, including in the specific account which is a moderator here, or in the web interface to this group (a natural place such a notifciation might appear), about this particular discussion-group under
groups.google.com.
Note that while Google had offered access to 'Usenet' via this same domain, not all groups at
groups.google.com are also Usenet groups – so any discontinuations of specifically-Usenet support (as Google announced ~6+ months ago) wouldn't necessarily affect all
groups.google.com content.
(If you're still concerned, when and how did you receive such a notification? Did it include a stable link to more details?)
- Gordon