Realistically speaking it's actually not impossible to think that 2P may not come back to SC6, even tho i hope that won't be the case of course. But TTT2 actually didn't had them, and T7 as well at the beginning until they got backlash about it and about the samey default, then they ended giving the character new default costume while setting the old costumes as 2P costumes. There are even still some characters in T7 that still don't have 2P outfits like Law, Jack-7 and the new characters.
It's quite ironic to see that Namco are actually getting ride of their own ideas they introduced themselves to the genre back then, meanwhile others fighting games like Mortal Kombat X and Street Fighter V are using it and expand it even more.