Oh wow, yeah, three options. Didn't realize he'd already had two in-season. Does the spring training one count?
Like Rule 5 it seems like this is another thing that is meant to give players more opportunities but can have the opposite effect. You either get buried in AAA longer as in this apparent situation, or you end up being fungible enough as a see-saw guy to trigger DFA.
Leaving him down there probably preserves his trade value too.