2.9 comes out in less than a week. How will that effect the speedrun categories and such?

I don't think the new update needs to be split apart from the version 2.0 runs.
Sure, the level layout is a bit different here and there, but there isn't anything that makes any category impossible or way slower/faster.

Ok!

What about 2-3? It loses 7 seconds

and the boss on 5-3 it's not zangief unless you beat the first 5 bosses

Thats true. plus some differences in pipes and such. it will be impossible to beat the any% world record from 2.0 in 2.9

in that case, i could add a category for the new version