Well, technically Garry Newman said Valve said since S2 is backwards compatible with S1, anything you write in the latter should work in the former. But, it would still probably need some tweaking and not sure every modder would want to do that or how long it would take.
It just sounds risky for established communities like this. Of course they could make a beta branch, but then the same thing would happen like with Dota. That not many would use it compared to the stable branch, and then eventually Valve would have to flip the switch.
It'd be interesting if they'd release a Source 2 Version with the intent of pushing custom content, like what Dota 2 did. Give us a proper menu for custom game modes, let us join them from the main menu etc etc. Just like how Dota 2 does it.
I think that might be the only way they could make it work without pissing the community off. If they say something along the lines of "while old custom game modes may not work anymore, here's an incentive to make them compatible with Source 2".
The incentive being that the game modes would get alot more exposure etc.
Interesting pic from reddit shows the windfall from the rank changes, makes sense how I dropped to MGE now lol. The scarier thought is that my coworkers that I queue with on my smurf were once DMG level.
Hmm.. that's interesting. I only dropped to LEM from SMFC, seems like I was close to global (which is hilarious and shows how broken the ranks were). But now it's totally out of reach haha.