Adam Jacobs has two young boys at home -- it seems more likely that he would try to stay with the New York production (if that's his intent) than lead the tour, I would think.
It's not uncommon for actors to remain in roles for long periods of time, especially if it's a long-running show and the money is good. As long as their contracts keep getting renewed, they're looking at guaranteed employment and a good, steady paycheck.
"You travel alone because other people are only there to remind you how much that hook hurts that we all bit down on. Wait for that one day we can bite free and get back out there in space where we belong, sail back over water, over skies, into space, the hook finally out of our mouths and we wander back out there in space spawning to other planets never to return hurrah to earth and we'll look back and can't even see these lives here anymore. Only the taste of blood to remind us we ever existed. The earth is small. We're gone. We're dead. We're safe."
-John Guare, Landscape of the Body