Link: https://nitter.net/TeamFortressS2/status/1745157814295617767
Valve is generally supportive of mods (hell, a Portal 2 mod was just released a few days ago) but it seems like recreating Team Fortress 2 was pushing it… Really sad, honestly. I really hope Valve would just strike a deal with these devs and make it official rather than throw away the insane amount of effort they put into re-building TF2.
https://www.eurogamer.net/valve-gives-black-mesa-permission-to-be-a-commercial-product