I'm pretty sure Boxberger is cooked so I'm not interested in him in particular, nor am I pining for a particularly different call up, though in a few days I'd probably prefer Brown I think. It's just a bit different than the normal reaction to a call up since unlike swapping out Little for an end of bullpen mop up guy, it's a fairly clear downgrade if it's Alzolay going to the DL(and while I hope not that seems the most likely outcome).
That said, the Palencia comparison, while true on the merits of control, does gloss over that Little has been much more effective as a reliever and better at the other parts of the FIP triangle. Even if he's walking a few more guys he'll be able to get away with more because of the obscene K rate and how no one seems to square him up (1 HR in ~130 full season IP). I just am gonna hold my breath if he's being used in a leverage situation, and in September in a playoff chase there's lots of those.