Now that’s surprising, so definitely qualifies as newsworthy. It’s a compliment, of course, but still unnerving.
What’s most unexpected is not so much that Facebook imitated chat.center, but that they didn’t bother to reach out to you, despite being aware of the product (the similarities you point out are highly unlikely by coincidence, so must be by design), and that your local (instead of a dev team in Kiev) and that you’ve been immersed in SV startups for decades.
That move is a strong signal Facebook is NOT founder friendly. Obviously, their PR staff didn’t attend kickoff meetings with this product team.