You could say the same about EDLS. I think they just decided Garcia's upside wasn't as good as they'd hoped last year, or at least, not as good as Rosso and Brogdon (who already already beat out Garcia for MLB spots) and Sanchez and Llovera and Cleavenger (and there are also guys like Jones who still have to be added to the 40 this year if they pitch). It also doesn't bother me that they want the experienced fungibles (Parker, McLain, Guerra). And some of those guys still gotta go if Arano and Robertson come back.
In a normal year you flip Garcia and Pivetta for present-day bullpen help, knowing you're losing some future upside. This year in addition to everything else they need 6 starters and are probably still reluctant to lose Pivetta (or Irvin) just in case.
It's also possible the PTBNL is fair value (or a trade asset itself), as in the original Luis Garcia/Alvarez deal. And ironic that we got Sanchez 'cause of the Rays' Rule 5 crunch.