I do love old man Bruce plus I think it's easier to justify if Eddie hasn't been the Riddler for years. And Terry showing up would be amazing too. Maybe some past scheme of Eddie's that involved Wayne Enterprises in some way comes back to cause trouble for them?

It was great and I am equally happy to make shit up or put that as 'when there's a little more canon to work with' option since we're going to be seeing a lot more of Bruce before anyone else.