No, If you have more than 4 un-managed teams in a 20 team league, and all steps possible have been taken to add managers to no avail; then the league should fold.

It's not a parallel situation for a number of reasons, but to keep a league open where HALF the major league players are not on rosters and unavailable to mid-season FA seems silly to me.

As I said, it's not a parrallel, and has no bearing on whether or not contraction in RT has any benefit in isolated situations.