DC is notoriously tightlipped about its movies; you couldn’t have gotten information about The Dark Knight out of Warner Bros. or DC with dynamite and a crowbar. Nonetheless, leaks do happen, and one seems to detail where Batman is at when Batman V Superman: Dawn Of Justice starts.
According to Badass Digest, Batman is firmly established. Like, really firmly. Like, he’s been around Batsuit and all for decades:
My sources indicate that when BvS opens Batman has existed for close to thirty years, which would place Wayne in his 50s. In this version Batman is still an urban legend, a creature of the night, and no one has ever taken his picture. But he’s had plenty of adventures, and the Batcave includes a memorial centered around a tattered Robin costume.
So, he’s been around. He’s been through at least two Robins, which indicates there’s an active Joker out there. And, basically, nobody’s noticed? At least Bats aged to be a distinguished gentleman, if these set leaks are any indication.
It’s pretty traditional that nobody thinks Batman exists at first, but it seems a bit of a stretch that he’s been clandestinely fighting supercrime for three decades and had lots of wacky adventures with absolutely zero awareness from the military, intelligence agencies, or law enforcement. Wonder Woman is apparently working under deep cover as well, and Superman appears to have blown the cover of every metahuman and superhero on the block by getting punched around Metropolis.
Honestly, that’s not a bad idea, even if they take it a little far. The idea that superhumans have been around and pitching in on the sly is a fun one that lets them explore some of the recent history while dodging some of the trickier questions a new start to Batman would raise. Just hopefully they don’t stretch the suspension of disbelief too far.