Some of this is a stretch IMO.
Reyna spent five seasons here (plus 1.5 years as prep) and had a chance to start fresh. Some people like building things more than running them forever. Maybe he wanted to see if he could build a winner without the CFG scouting and special deals. I think especially with SDs, and maybe outside of MCFC, CFG requires people who are willing to temper their ego and give up some control in return for lots of help and advantages. That has upsides and downsides. But you can't deny they won a lot of championships around the world. With 2 sporting directors in 9 years NYCFC has been pretty stable. Coaches not so much.
Torrent's departure was weird, but I've always had a low opinion of his temperament, and he clearly never got over the Arteta/GVB rumors and learning he was on a short leash in early 2019, but damn, he had led the team to 18 points in 19 games (over 2018-19) at that point. It was ridiculous to expect the club would not be looking at alternatives after that horrific slump. Boo-hoo it took time to sign a striker in early 2019. In 2018 he took the best first half team NYCFC ever had and ran it into the dirt.
I don't like Ronny leaving or midseason coach departures in general. I actually kind of hate it. But once they set the terms with PV, and added a buyout price clause to Ronny's contract, that ship sailed. The CFG devotion to letting coaches and players set the terms of when they leave - which lots of people support - has a significant downside in a league that both isn't top 5 and has an offset schedule. Generally the leave-when-you-want approach has both upsides and downsides, but IMO the midseason coach departure has no upside. I also agree about the interim issue, and I had hoped that elevating a coach from within would lead to a smoother transition (and to be fair the results so far aren't bad) but I don't like the instability of making him interim.
Now Palermo doesn't look good. The team went to pieces in 2019 over financial irregularities and was excluded from all professional leagues in Italy. They did some corporate jibber-jabber and started fresh in Serie D and moved up two years in a row to reach Serie B this year. Then CFG buys them, keeps the people in charge, but they quit about a month later, citing control issues. OTOH, for all I know, CFG will put in more CFG-type replacements and keep up the success.