I have never trafficked much in speculations about my chair, my dean, my provost--let us call them "the administration." I like gossip, my colleagues in the university believe their gossip is well grounded in actual facts and policies. I have no idea. If someone does not get tenure, either the administration is arbitrary or changing the standards; if someone leaves, the administration did not try to retain them; if someone retires, the administration has forced them out. If a dean does not continue beyond their current term, the provost is out of control,... And so forth.
I am sure there is some truth to some of what I hear. But of course I never hear the other side: X was not strong enough as a scholar; the attractions of a new position could not be matched by the administration; the retiree has perhaps become less effective; and the dean is not delivering to the provost's expectations.
I do know that it is the provost's job to decide on tenure (the university committee is advisory, not at all determinative), people are let go to other places as a nice way of reinvigorating a faculty, the retiree is actually getting a nice deal for retiring now; and the provost chooses deans and is responsible for who they choose and retain.
If a university is trying to become stronger, there is likely to be disruption, and the situation will get even more tricky. I doubt there is much of a conspiracy, although I am also sure that some moves are meant to help a spouse or friend and they are fishy.
I have found that the best advice I give on promotion and tenure is objective judgments about the quality of the case, and by implication the quality of the candidate. My main concern is improving the quality of the university and making sure processes are fair. I leave to the provost matters of sympathy or special consideration. If I would not trust a dossier, for whatever reason, the provost needs to know. If someone is ok, but not likely to continue to be strong enough, the provost needs to know. And so forth.
The buck stops with the dean or the provost--not with me.