There's no need for a vote: the vamps and wolves are already about to go to war. The East End Pack are making a territory claim on the Islington Nest later this month which is going to kick things off anyway, so this plot is easy to work in as part of the rising tensions. It all fits rather nicely.

Of course, you don't have to have Johanna be identified if you don't want to, it's probably easier if she was spotted as a wolf but they don't find out who she is. Islington thinks an East End wolf murdered one of their own, the East End Pack are all "don't look at me" and then boom, territory claim.