Timkon clon baby au but Bruce loves his grandson way too much he stops being Batman for a while to help single teen parent Tim being yk a parent.
Like, he's soooo down to being a grandfather that as soon as he sees the baby in Tim's arms he doesn't even asks where it comes from he's just omgomgomg a babyyyy.
Because, yk, he never got the chance to hold his kids when they were babies and now he can hold the baby of one of his babies.
Enter making the mannor baby proof on day one and making a whole room a playground!
And he sees how Tim is like, not okay, like, yes he's happy he's a father now, but the grief of his friend dying is still there and the guilt of trying to clone him AND successfully doing it is not going away quickly enough for him to be able to take care of a whole human being, so Bruce of course steps up (because he's a good father when he needs to, AND THAT'S A BABY OK).
So, being Batman vs being there for his son and grandchild? Obviously his family needs him more.
So pretty much everyone commits to the cause.
Dick can be Batman for a while, just like once a week so Gotham knows he's still there. Jason may help a little by not causing trouble and Cass is so down to watch the kid 24/7 because they don't know if he has powers yet or when will they appear.
Just a big bat family trying their best for the new baby!