If RSE does take place is the past it could have the PwT (with Alder participating rather than either Steven or Wallace depending on who they decide to keep).
I just had a though, perhaps they could keep Steven for the Ruby remakeand Wallace for the Sapphire. Steven has to do Steel and precious stones which can be found in the Earth (ground) while Wallace is obvious...plus it could be a small hint to DP remakes...though it could be vice versa like how Hg had Kyogre and Ss had Groudon (aka 1 ( current remake )-2 (future remake) version 2(cr)-1 (fr) version.)
Also whoever says that Gen VI is going to follow B2W2 simply due to all gen V events being released are forgetting that Arcues event was followed by remakes and like four or was it five... events (the last which connected to gen V) for said remakes (Mew, Celebi, Soul Dew, Shiny beasts...which would make it 6, and Manaphy (7)(Idr if this was just japanese or if it came to the Us as I didn't get it...).