This is a BC feature already.
I know a few 08ers that said back in the day you could change the max players with scripts, but ROBLOX has now reserved it for BCers (mega servers and whatnot).
So suggesting it be for everyone is a WNTS.
This is just a bad idea in general. If people started doing this then the forums would be flooded with complaints and player count would fall to oblivion.
Hmm, that too. I could see that, like if you are testing something and you only want a few people to do it at a time. Support (don't know if I already said it but...)