I know it's unlikely to see those characters, but you also have to keep in mind how much the creators behind these series love the DC Universe. You're playing with time travel in a variation of the DC Multiverse. That in itself would open the door down the road for any Batman/Superman integration into the CW-verse shows. Flashpoint, Hypertime, Multiverse, etc... DC's used time travel extensively to retcon and expand their continuity. The last big time travel story resulted in the New 52 and the integration of Wildstorm and Vertigo into DC's universe.
Hell, if anything, you've got a backdoor to eventually bring in Supergirl if it ends up cancelled over on CBS.