Only 4 of them. Edmonton, Quebec/Colorado, Hartford/Carolina, and Winnipeg/Phoenix.
The NBA took in 4 survivors of the ABA, too - Indiana, San Antonio, New Jersey, and Denver. All of those changes took place when the ABA and WHA folded, and the surviving teams were accepted as expansion franchises.
But neither the ABA nor the WHA would have accepted that they were “minor” leagues - they competed for players directly with the established leagues, even though they had fewer good ones, and were in smaller and less lucrative markets.
I knew that the ABA was a competing, if smaller, league. Sorry if that was unclear. The WHL, on the other hand, I had no idea about. I thought it was a minor league like the current AHL.
And in the case of the AL, WHA, the AFL, and the ABA, they were competing directly with the NL, NHL, the NFL, and the NBA for revenue. The competition was settled with mergers. The older leagues allowed the younger leagues into the co-op so that they could stop competing and be monopolies again. This emphasizes that in American sports the basic economic unit is the league, not the individual club. Those who share in the ownership of the league are allowed to field teams that compete in the league.
That’s essentially a restatement of ElvisL1ves’s point, though. The Toledo Mud Hens exist to serve Detroit, and as a consequence their roster moves don’t have anything to do with what’s good for the Mud Hens. Same with almost all the other minor league teams; their best hitter might get called up on August 1 because the parent team needs a backup outfielder. It’s not the lack of independence in and of itself, it’s that it results in the team’s roster serving a need other than the success of the team.
The saving grace of that is that a large number of minor league teams are affiliated with the nearest MLB one. Toledo, for example, is in Detroit’s sphere of influence, and if you were to ask a sample of fans at a Mud Hens game who their favorite team was, they’d say the Tigers. There is some enjoyment available in watching a player develop in front of you and become a star with your favorite big-league club.
Plus, tickets are much cheaper and seats are much better for minor league games. They’re not necessarily easier to get, though - the Boston Red Sox’ 3 New England affiliates sell out every game just like the big club does.