(Assuming of course, that he -- like many AmChurch bishops -- exercises a certain independence from Rome. I see no reason yet to ascribe this decision to anyone but Egan himself.)
If a shortage of priests is the reason for this move, perhaps a death of traditional and faithful parishes is the real problem that needs addressing. In any case, I fail to see how recalling Pavone is the Only or the Best Option he has for filling a slot.
Perhaps he could check the rolls of "ministries" funded by the Campaign for Human Development and find a still-frocked priest able to fulfill his sacerdotal -- instead of Peace and Justice -- obligations for a change.