Highly favored teams that lose in the LDS seem likely to react to it by saying "freak it we're signing whoever this year's Gerrit Cole is" than by saying "the playoffs are a crapshot, we're going to trade Yu Darvish" so it does not make sense to me to say that expanded playoffs decrease the incentive to create superteams. But again the MLBPA has much more at stake and has likely done far more analysis of this question, hired more consultants to study it, etc.
