Imagine if they continue with the DCEU, in the sense that SS.2 is coming out, flash, Shazam, WW, AM all seem to have life in them, regardless of Reeves etc and Ben cameo'd once in a while, it's unlikely, but hey, a week on set and a big pay check, you just never know.
Personally, I would prefer him more as Wayne, his images on tv, the cover of a magazine and in the DCEU a new saviour steps up in Gotham.
I actually had this cool idea, at least in my mind, that the next SS sequel happens alongside the events of Knightfall.
Imagine a scene where let's say WW3, she contacts Bruce and he is on the other end of the line, looking beat up, he explains something is going down in Gotham but he seems to have it handled. as news reports show a new terror figure is in town known as Bane. Diana is worried but respects this.
Then in the flash movie, we see Barry reading a news article of what's happening over at Gotham and one night he appears at Wayne Manor and chats to Alfred who seems concerned but makes out it's business as usual.
Then, over in the SS sequel, it starts off with Waller calling in a team, they ask why and she turns on a tv and we see news reports of Batman, recorded grainy on a camera, we see him being beat by Bane and his back broken.. and the SS is enlisted to hold order, of sorts whilst the GCPD get their ****e together and we see the aftermath and the rise of other vigilantes and bat family and then JPV.
I just think it could be cool. Then, when the JL reach out, it's Alfred at the door, insisting bruce is ok but needs rest etc and Alfred looks broken but they respect him enough to listen.
So a linear story is occurring, that deals with the absence in a way better way than, how, in my opinion, marvel handle it.