Kendrick is actually a test of the new front office. Klentak has a previous relationship with him, and one of those recent articles said the team's analytics suggest he is capable of bouncing back. I like hearing that better than thinking it's the GM's gut feeling, or that they think he's an exception to data or the aging curve, as was so often the case with Amaro (his first signing as GM, he celebrated Ibanez's reverse platoon split).
He's pretty cheap, so if he bombs they should be able to move on pretty easily. Still, so long as he's not a complete disaster his trade value should be ok, he gets on base (still would have looked good on last year's team in that area) and he can also play 2B. Phils will pay his salary. That's not to say they'd get a big return, but they could move on w/o cutting him. His presence also means it is still theoretically possible to trade Galvis or Hernandez at the deadline. Klentak clearly likes options.
Mostly though, as with last season, I think the issue is not merely confidence in Kendrick or Mackanin's desire for vets, but wanting to keep Quinn and Williams in the minors for a half-season, unless they play their way into a May call-up (ditto Crawford). In the meantime, Altherr as 4th OF should have first opportunity to unseat Kendrick, since he can't unseat the lefthanded Saunders.
Kind of a funny subplot to all this IMO is that while Pete gets his veterans, Wathan gets to manage what, in a perfect world, will be most of the 2018-2019 line-up, playing and growing together, and possibly with him as their major league manager. I would bet that has at least been a topic of conversation in Klentak's private meetings, letting these players spend several months starting in AAA together and letting Wathan continue to manage them for a bit.