Real team progression for the 19th century (disband teams works with the minor League so I don't see why it couldn't work in the major league) + UA and PL
Minor leagues before 1914... the players are there starting in 1886 so why not? It isn't different than adding the FL in 1914 or the Negro Leagues.
maybe next year, I can always hope
And I can't understand why it isn't done yet: In the game record page please add "Major League" records... the team records, the NL records, the AL records are there so why not the ML?