As much as I love the PWT, to me it was always obvious it wasn't canon (save the Driftveil Tournament), which is why characters such as Bugsy appeared not having aged a day. So in that sense, I'm sure it's possible to have the PWT similar to how it was in B2W2 (aka without Bugsy being 3 years old); however, I see no real point in bringing it back, at least for these games. I loved the eternal daylights out of the PWT, but why have that when they can reintroduce the Battle Frontier? Emerald was the first to feature it, after all. Having both is a possibility, but as was already mentioned on this thread, the PWT is essentially a replacement for the Frontier, so having both might be a bit overkill. Also mentioned was the desire to have Gym Leader rematches that provide money and experience, and I feel that having one would mean sacrificing the other (and again, Emerald featured the Match Call, so I see no reason not to go with it).
Basically, if we could have our (non-canon) PWT along with the Frontier and Gym Leader rematches, I'd be happy. But if having one meant sacrificing the other, I'd much rather go for the Frontier and rematches.