Valve has a few hundred employees compared to the tens of thousands in Ubisoft/Blizzard/Epic. They ignored HL3 because they couldn't spare more people, they poached developers from CSGO for HL:Alyx, and with the 2 new VR games and source 2 for CSGO, TF2 isn't a priority. Whatever skeleton crew is still working on it is only doing it between projects. If you're going to get even scraps of attention from Gaben, it's only when TF2 has a huge competitive playerbase, and pubbers aren't going to suddenly changes their mind about comp TF2.
Just get the promod, make TF2 more enjoyable to play first and promote shit like newbie mixes and creators.tf