Whizbang Dustyboots
Gnometown Hero
It's been 20+ years. The people who are going to give a crap aboud slaadi and modrons do. No one is going to bust out a brand new exciting way of looking at platonic solids with arms and legs that hasn't been brought up before now.Yeah, sure. But this is essentially making "new IP." You shouldn't replace the older versions of these things, so you're in a situation where anything you make is unable to connect to an existing network of fans. It has to stand or fail on its own merits. And it's easy to fail.
If you're going to have Limbo, and you're going to have a Clockwork Nirvana, you're better off using the stuff that's already there for them, presented with all the awesome possibilities they have inherent in them. Someone invented these things in the first place -- someone somewhere thought they'd be a good idea. The focus in this case is getting to what makes the idea good, and using that as the driving force.
So, the choice is this: Let them sit off to the side a bit for the people who love them to get to use them, more or less unmolested, or WotC will tinker with them -- or, in all likelihood, them up beyond all recognition of the people who love them today -- in the hopes of reaching a broader audience.
Of those two, for the people who love them, putting them off to the side is the better option, IMO. It's certainly what I would have preferred with gnomes in 4E.