I will now be personally headcanoning that Bruce pulled Tim aside one day to ask his opinion on if Tim would ever consider changing or adding Alfred to his middle name(s). I've always interpreted Jack Drake as having been abusive towards Tim, due to some of the comics where he's been violent and such (Like the time he destroyed some of Tim's belongings and such when he was angry at him, or the straight up neglect when Jack and Janet went to explore the world regularly and leave Tim behind, forgot his birthday, etc), and so I feel like sometimes Tim would feel icky about keeping his middle name as 'Jackson' after his biological father (I'm surprised he ever kept 'Drake' and didn't just fully move to 'Wayne', but alas). I feel like Bruce would also be aware that Tim sometimes feels left out of the family, especially due to the early years of him and Damian's dynamic and constantly being told he was never Bruce's 'real son'. It doesn't take a lot of common sense to realise those kind of words will linger, even after the brothers have improved their relationship. I had originally thought to consider this with Damian, but he's already named after Thomas, so I feel as though Bruce would choose Tim so that he gets to both honour his second father, and let Tim know that he will always be Bruce's son and a part of the family, regardless of DNA. Tim accepts, and so his middle name becomes Alfred, instead of Jackson.

Alfred doesn't find out until he's going over some family legal documents and sees it. He cries when he does.