You know, I'm wondering if it is Booster who will bring back Bruce Wayne. To be fair we know Bruce is in prehistory. We know Tim is going to find the bat that Bruce was painting in the cave (where they found the symbol to keep out the antilife equation) via previews.
So I think it is going to end up having Tim running into Jamie who will have some strange recording of his adventures with Rip/Booster even though the memory was removed. They will find Booster and go back in time to rescue Bruce.
I know, long stretch, but come on am I the only one seeing the interactions with Bruce and Booster right before FC and saw that Bruce had gained respect for Booster, and that this would be the final way Booster could repay him for his faith?