Certainly some truth to that. But sometimes the other team just has someone better or more ready, and the Phillies didn't (and traded away one). He's also still very, very young. He just shouldn't be in the big leagues.
Certainly they have pieces that can fill the spot - whether that means living with what Guthrie brings as a CF or using Rojas or Muzziotti purely for defense (unlikely, but might happen eventually). Kingery may also force their hand with the 40 if he keeps doing what he's done the first three games.
Really - even if this is just the bad start talking - the whole philosophy of trying to improve the defense around the margins probably doesn't make as much sense when the offense is missing two of its four most productive bats (from last year). It might make more sense at full strength, or if there was just the one short-term absence. But they needed Hall w/o Rhys and now they probably need Hall and more oomph rather than Hall and more defense.