If this fight actually happens on schedule(I think there will be some trickery from someone to delay it), I think Joshua will win it by stoppage, I suspect fury is a bit of a nervy guy who struggles with being the favourite, Joshua seems a lot more comfortable in this role which will help in a big fight like this...

Fury to frustrate Joshua in the first half of the fight and then Joshua goes a bit wild and puts fury down and out in the second half of the fight.