I'd read it, but there's the problem of being too revealing. We'll never get characters who know too much about what's going on behind the scenes as perspective characters, unfortunately. Monsieur Butcher even joked that he couldn't do one for Mouse because he's clued in too much—though know we're getting the Zoo novella from his and Maggie's perspectives, so I guess there goes that point.
Anyway, I'd read the hell out of it. Honestly, one with Erlking, Kringle, and Eldest Gruff hanging out and building their three-way bromance would be awesome.