BGE Python does not need to be in a different subsection. It’s a general component provided within the engine, and as such it should be more than adequately handled within the current forum structure.
Just because you can split something out into a different section, that doesn’t necessarily mean that all the resources within that area automatically improve. I think this stands true with python, in relation to the BGE.
However, a specific sub-section for GE development could turn out to be very beneficial in bringing the development and user communities closer together. That is; as long as the current developers agree to create and post some tutorials/resources that the rest of us can use, in order to make our own modifications somewhere down the line. Also, we as users should try to keep our usual crap out of that section.
Otherwise, that forum would probably be nothing more than Kansas posting about what he would like to see happen, along with all the other idiots yapping about “wouldn’t it be cool if it could do this” or “I need someone to implement this feature for me”. -> In other words: a whole lot of bullshit.
So, it’s something of a gamble either way, because it depends on so many different people - but I think it’s worth a try in this case.