Unfortunately they haven't been leagues in the organizational sense for several decades.
And at least finally this might bring some darn consistency with the designated hitter rule.
league /lēg/
noun
An association of states, organizations, or individuals for common action; an alliance.
An association of teams or clubs that compete chiefly among themselves.A class or level of competition.
"The ski jump was out of his league."
Since interleague play is a minority of team schedule, I guess that point could be debated.