Well, obviously if they combine worlds, there is still only "X" number of the really good baseline A+ teams (Kentucky, UNC, Duke, Kansas, UConn, Syracuse, Michigan State, Illinois, UCLA, Arizona).
All those teams are filled in every world, therefore you will have 1/2 the A+ prestige teams and all the coaches who had an A+ prestige team. A couple of them might have A+ prestige teams in both worlds, so they would only get one. You would still likely have 20 coaches (2x10) go down to maybe 18 coaches (2 guys with A+ in both worlds). That still leaves 8 coaches without an A+ prestige team.
Now, I am fine with that at this point (I don't have one of those teams :D) .. but it is unfair. Those guys have been paying customers for years and years to qualify, so screwing them would not be good business.
Now, one thing I think everyone can agree on (or at least most) is a team reset at 25 or 30 years. Once you coach a team that long, you have to get a new job. You can keep your last 10 years of prestige as a coach, apply for new jobs that are open, but your team opens up.
I can't see contraction, however. That would be extremely bad press.