Bergamot was there for at least months (for example, the JD for the Bergamot-Mozilla collaboration was posted before this May [1]) and only advertised a few days ago. It is most likely a coincidence, given that Google and Microsoft has full rights to complain to Mozilla. Or, in the reverse direction, they may have complained because of public articles about Bergamot.
[1] https://web.archive.org/web/20190520103652/https://careers.m...