I don't think it's shock, it's just kinda of annoying to see a new character on the alliance side be this strong out of nowhere in the middle of the third act of an arc. We're okay with villains like this, because it raises the stakes, but when an ally is that strong out of nowhere it cheapens things a bit, it actually lowers the stakes, wich are almost 0 in Wano already. That's how i see it at least, if it's confirmed she has CoC and Advanced CoC later on.