No way I can find without a third party-app, anyway. I tried changing the function that is mapped by default to three-fingers-down (App Expose) to see if it would 'free it up' for mission control, but no dice.
I'm finding a lot of things like that (reversed scrolling!!!) less comfortable/intuitive, but trying where I can to just get used to them, as I expect they'll feel just as good eventually, and if so, will become standard practice all over the place. (Yes, I know that "get used it" isn't what you asked for, but on this one, I don't think you can default to the old method you used for expose.)