It's been talked about before, but nobody's really expressed much interest in it. Of course that doesn't stop you running what you want, but it'd look silly to have a bunch of categories/sub categories with no runs. Especially so on the main leaderboards
People don't introduce Orb/Cloud into runs, mainly due to the fact that Cloud only really saves time in the shorter categories. Orb can be made consistent, but relying on a glitch that can crash the game (and ultimately the run) if done poorly, doesn't entice many people to inject it into their runs. That's why Orb is generally considered more for the Extra Categories leaderboard runs and 11-Exit (mainly for legacy reasons).
As @Xander479 states "that doesn't stop you running what you want".
Sidenote: What you suggested was actually done as an April Fool's Day joke. There was a route created for 96 and everything. Except, only 2 people ended up running it. Here's the route sheet: https://docs.google.com/spreadsheets/d/1NoYLsBcUT6uxSwtwYoNb01u8sQyPAkYs0HUHc1dnFKs/edit#gid=0
It's something that being looked into as it's easily been the most suggested thing to me by various members regarding leaderboards.
I've always thought it made sense since this is the most natural any% category that any new person would attempt. It's a very pure form of any% for SMW, and most games seem to have their version of "Any% NMG" (Basically a natural any% run that doesn't totally take the piss by warping to credits, save corruption, etc). Its ruleset is also fairly pure (Any% NMG based on our current NMG definition) and is easily and by far the most run category on the boards.
I've also thought filters are generally a bad fix for this type of thing since they put off a lot of runners of submitting each run type. A good example is the SMB3 boards putting NES/SNES together, making it that there's literally only 6 all-stars submissions there even though are lots of runs
Speedrun.com's emote tech isn't advanced enough for an appropriate reaction to over 300 run verifications!! GG! Usually I don't think I'm even aware who's gone to the effort of verifying so gg mods!
