
Yeah there's no technical reason it couldn't run on iPhone but I'm not sure they will do it. Rertronyms did all the heavy lifting (I shouldn't say heavy as the app is missing - sample folders, proper sample chopping, mute groups and pad mute MIA, 1 bank instead of 4, no panning per pad and so on.)
Tabletop being iPad only makes me think they keep it on iPad. And so far I've found that hosted in Tabletop is the best way to run the app. I know you can have at least 2 MPC's loaded, I have to see if the quoted 8 track limit is set in stone. An iPad HD or 4 should be able to load 8 of those modules CPU/Ram wise.
But yeah I think it may be a long wait or never as an already feature poor app would be that much more crippled on iPhone. If they make it Audiobus compatible though, that would make it more feasible for the users and maybe makes Akai more apt to do a small screen version.
If you're iPhone only you're aren't missing much next to Beatmaker2 and Nanostudio. Although it was a better experience as a Tabletop module with an MPD when I tried that.