Multi Region Game

Ok so I know there are a lot of people who want a game that has multiple regions in it (a la gold and silver) and I also know that there are people who say the format of Pokemon can't support games with more than 2 regions (Pokemon get too strong, too easy then ect.). So my thought was remake diamond and pearl (obviously) but post elite 4 throw in a curve ball instead of the battle frontier. Dialga and Palkia control time and space, so post elite 4 why not there be a rift that opens up at the sky pillar and the player walks/falls/dragged through. This takes the player to an alternate reality where the bad guys (Team Rocket as I love gen 1 and 2) won. Lets say in this alternate reality Red didn't defeat Giovanni and team rocket have successfully take over the 2 regions. The player could wake up with no Pokemon (as they were left in the players own reality) and could help the resistance fight back for control.
Im not sure how gym battles/ elite 4 would work in the alternate reality, this was just an idea that sprung out of boredom.

GSC and HGSS are most likely the only multi-regions to ever happen. I do not think we will get anymore. Plus the concept had some flaws that was noticed by fans.