I'm not even sure if we'll get a Capcom character in the Fighter's Pass (there are already three in the base game, though only two of them are unique), but what would Monster Hunter bring to the table? I get Amaterasu, I get Leon Kennedy or Jill Valentine, I definitely get Dante, I even get Phoenix Wright, but I'm not sure what would make Monster Hunter interesting to play as.
Maybe it's my lack of familiarity with the franchise (I've only played Monster Hunter Tri for the Wii), but it seems like there'd be a decent amount of overlap with Cloud or the Fire Emblem cast, combined with some traps as specials. (then again, in my experience, attacks in that game are either clunky and slow or too weak to kill anything within the time limit, so maybe I just haven't found the right play style)
I just figure that there are so many options for a Capcom character that I'm not sure what makes Monster Hunter stand out above the rest, especially since (unlike most of those other franchises) it doesn't seem to have a main character with a stable identity or moveset. I'd be interested in finding out, though.