As there will soon be a new edition coming to Xbox One and Switch, and PE becoming the main edition, does that mean that these forums will have a big rearrangement when this happens? If yes then I have a concept idea as to what forums we will have.
Main edition discussion (current PE and Windows 10 along with new One and Switch)
Edit: As for your concept, I'm not really sure how useful it would be to have a non-edition specific discussion area, since most people would probably still be talking about a specific Minecraft platform and I would expect there to be a ton of wrong-section threads in that area. From my own experience on the forums, I really can't say that I have seen all that many discussion threads that would truly fit in a section like that.
For the creative and survival mode sections, I would assume that in the console sections, those areas are just merged into their respective discussion sections, whereas the PC version has those areas split out due to how much traffic those areas were originally expected to receive. I am not sure they are meant to be non-platform specific, and I am not sure how useful areas like that would be for the same reasons as the non-platform-specific discussion area.
Merging all the PC Minecraft areas into a single forum group might make for a very giant and confusing area, considering how many sub-forums are used (and really required) in the PC servers, Mapping-and-Modding, and SYC sections.