The problem with the comparison is that 11's movement feels bad, but not simply because of one reason that is easily fixed.
It had a bunch of issues that came together to make it feel sluggish.
MK1 seems to have fixed aspects of it, walk speed is faster, the initial acceleration is faster apparently, these two things go a long way to help.
The stages seem a bit smaller, and fireballs do seem to have a lot more recovery, which also helps.
Dash's could definitely be sped up though, remove the weird dash cancel thing, and just make them faster by default.
When people are talking about MK9 movement, a lot of them seem to want dash blocking back, which lets be real is never going to happen, it is forbidden, it is the forbidden dash.
It already looks much less mush then 11, but, I don't want less bad then 11, I want it to feel good.
But hey, it sounds like the devs at the even were very eager to hear peoples opinions on the game, so and to rectify what people disliked about 11, so if it isn't up to snuff, lets hope it can change.