I always hated the planescape "reboot" of these creatures.
The original MM2 shows them as geometric shapes, not clockwork robots. I thought it was a lot weirder and more original than going to the clockwork/steampunk cliche. Biological creatures of order so alien the masses appear as near-perfect geometric shapes, while the leaders are humanoids that can't pass the Uncanny Valley.
If they were ever to come back, I'd like them to consider this aspect.
I think you're looking too deep. I really don't think it was anything more than 'dude, what if there were monsters that looked like dice!'
Not a modron fan. They're nearly as dumb as gelatinous cubes, piercers, and mimics.