The ending is Not like the Inception ending. If we were to assume for a moment, just for the sake of argument that Gordon is imagining the Bat-signal is restored, and that Fox is imagining that auto pilot issue is fixed by Bruce and that Alfred is imagining that Bruce is in the cafe in Florence, that leaves Selina's character, why she is not imagining something too ?
So, Is she also imagining the same dream that Alfred is having about a cafe in Florence, but then she never knew Alfred that well, and how can both have the same dream ?
Maybe, If we assume (just for the sake of argument) that Only Alfred is dreaming about that cafe, then why he sees Selina ? Alfred knew nothing about Bruce and Selina's relationship.
And what is Selina dreaming ? It seems odd that each character that is close to Bruce is imagining something (Fox, Gordon, Alfred maybe even Blake) then why leave out Selina Kyle?
The only explanation is that Bruce Wayne survived and left some clues to Gordon, Fox and then he met Selina and went to cafe knowing that Alfred will show up there so as to assure him that he is alright and he has moved on with his life.