I would think that Moraes would start but that Bravo will come in if required, and if he plays well then he can keep the shirt. It's quite feasible that in his 2nd season Bravo will recapture the form he showed for barcelona
Bravo's problem is that Ederson will have to be as bad as Bravo was last season to get dropped.
And even then, we've got a lot more invested in Ederson, and he's a much longer term prospect, so we've got even more reasons to persevere with him even if he starts badly.