I was a one time contributor to a project which made me a "collaborator", and now I have new feed items when they fork a repository.
When I login to github I just want to see my repositories or profile, I'm not interested in whatever this is.
EDIT: After browsing the product feedback forums, it is apparent that this issue won't be addressed and is unlikely to be reverted. I'll be cancelling my account and moving back to Sourcehut.