As for pipe dream... so was integration and west coast teams at one point. Think MLB seriously thought about San Francisco in 1902? Or black players?
It's simple progress. The thing about progress is you almost never notice it until you look back. The great ones like Walter O'Malley look forward to see it and seize it.
There will be some rich guy that wants an MLB team in Mexico or maybe another Canadian team. Maybe both at once and MLB expands to 32 teams. It will happen because MLB never refuses more money.