I feel like his weaknesses of last season will be exposed in a more extreme manner.
His leadership skills will be tested differently with a worse roster, where the buck stops with him. This is especially true if Brooklyn can't get any other star talent, as is rumoured to be the case with Durant because he has a fragile ego. Brooklyn is similarly young, but with less talent (but also, I would assume, less ego).
There will also be worse players to defer to, which he may like. But I think the fact that defences will be trying to beat him up will be bad for him. Once he concedes defeat he becomes a much worse player, and I can see that happening with more regularity in Brooklyn.