Although he may have left his franchise days behind him with The Dark Knight Rises, it could very well be that Christian Bale could be stepping into another one.
In an interview with MTV's Happy Sad Confused podcast, Christian Bale confirmed that he had "a discussion" about possibly joining Solo: A Star Wars Story. "Yes, (it was) very tempting. I not only love the films going back to my childhood but also have a very long relationship with Kathleen Kennedy and Frank Marshall because they did Empire of the Sun many years back. There was discussion, (and) I hope there will be future discussions."
The role that Bale was up for, according to THR's Borys Kit, was the role that eventually went to Woody Harrelson - that of Beckett, Han Solo's mentor and father-figure. Bale didn't explain why he didn't go for the role, but it's quite possible it had something to do with his transformation for Adam McKay's upcoming biopic on Dick Cheney that has seen the actor balloon in weight to get into the role.
The other part of the quote, however, is interesting - namely, that Bale seems ready to join the Star Wars universe in some capacity. Given how intense an actor he is and how he so fully throws himself into roles, seeing that in the light-hearted environment that Star Wars is may not necessarily work.
That said, there was a rumour going around just after The Force Awakens that Daniel Day-Lewis seemingly had a meeting with Kathleen Kennedy about a role - so who knows what's in store?