Japan's meta game for Brawl developed largely by limiting comp play to FD which when it expanded to include BF (in in super rare cases SV) ended up helping the overall meta game so I guess it makes sense to focus on the FD only (flat) approach and then branch out from there. But it's too soon to tell, really. There could be quite a few CP stages that are viable. But remember Brawl brought on a lot of argument between camps, those who felt FD/BF/SV were the only really legit comp stages, and those who felt those made good "starters" and that there were legit cp's after that. This new approach to flat versions of multiple stages suggests that the entire starter/cp system would need to be rethought and perhaps done away with (ie starters would be any flat stage, then cp would be non-flat). Or even still there may be variation WITHIN the flat stages, as in some may be longer flat surfaces than others, to accommodate various modes, like teams.