Your personal preferences aside, there is no reason why a Planescape version set in the current cosmology couldnt work. The fact that you like the current version doesnt mean a new version would be terrible or a mockery of the old.
Except that Planescape was literally created based entirely on the great wheel and the series of alignments. There's a LOT of narrowed eyes over the idea of a Planescape based on the new cosmology because it IS an incredibly radical change, and one that does not bode well for the setting. To put it another way, imagine if they made a new Spelljammer, but without the space. No more going into space. Instead, it was stuck on one world, and you sailed in the oceans. Sure, I suppose it could technically work, and undoubtedly there would be people going "FINALLY, a setting for Spelljammer that makes sense! I've been houseruling out the space since the dawn of time!" But overall, it simply doesn't work with the setting.
Not that it matters, as 4e is ironclad about "Find thing, kill thing, loot thing," which is about as opposite as you can get from Planescape, which is why I, personally, don't think we'll be seeing a 4e version of it. And if we do, it will be one that makes people weep. Not in a good way.