I guess you could argue that it was mighty generous of the Phillies to exercise all the coach's contract options, since they were in limbo for two weeks. They will be be free to pursue other jobs and the Phillies will also be free to replace them if the new manager wants, would probably just cost them the price of a Phil Gosselin (at most) if they ditch a couple of guys.
But there's not much to like about this, IMO. At best, Klentak gets it right the second time, or a veteran manager is forced on him but they are able to find a good mix and collaboration and both Klentak and the new manager are here for the next four years (manager, if it's anyone of note, will get a three-year deal and if the team is in the playoffs the next two seasons Klentak will get an extension). But if next season isn't much better we'll be doing this all over again, maybe more than once (if the new GM ultimately wants to hire his own manager).
Showalter would be the big stick, really. He wouldn't just want more say on the field, he'd want more say on the roster. But the reality is, the collaborative nature of the GM/manager relationship, including the selection of coaches, isn't going to change, and that's not just a Phillies thing at this point. Maddon didn't get to hire all his own guys in Chicago either (one of them being Mallee, so....)
The nine rehired coaches are all mentioned by name in the official press release.