Fun Fact: the Devs ARE going to connect all the regions.
lets say for example. your in Johto correct? and you want to go to Hoenn, theres a Ferry where Jasmine's Gym is. (i forgot the port city name)
from there its required to have at least 5 Badges of anykind. and you can go to Slateport as your starting area.
which would be the same as everything else. but however if you think about it. look at this map below....
View attachment 662
Currently you can go to Hoenn from there. which also the Orange Islands is also in progress, which me, Darkfire, and Prince Vade are working on.
i brought out this map as an example on how the Ferry Routes can connect to each of the Regions
which would also mean that if the game is based off of this map, then in order to go to Sinnoh you need to head north and come up with a new Region but with mixed Pokemon. get me?