Personally I don’t see anything wrong with these collaborations, this Saturday we are hosting an event on a mod for Battlefield 2 so where is the difference? 
To put your comments in perspective, this is the most viewed collab: Classic Game Night - May The 4th Be With You - Galactic Conquest (Battlefield 1942) - Dark Rendezvous
These battlefied games are old time classics, and they just so happen to have extensive mod support that not all newer battlefields have. Sometimes it’s funnier to difersify and host an event on a mod than on the classic game itself (2 out of 3 of my BF2 collabs so far are on mods).
I think you guys are misunderstanding each other, Posi is not “investing” (there is no monetary return, he doesn’t charge you to play, or to download the mod), what I believe he tried to put out there is the fact that he’s personally paying for the server where the event will play out.