I think with Gravenberch you potentially have a player who will enhance your offensive transitions. And along with Kimmich, the creative burden will fall on players like them, who will be expected to provide the class and guile on the ball in the build up phase. Gravenberch is still a teenager and will need time to grow as a player in a much tougher league playing for a giant club. But as far as profile goes, he's a player that is best utilised in offensive transition. And the rest of his game will potentially improve with further development.
Goretzka is a box to box midfielder that isn't going to be the pulse (metronome) of the team like a Kimmich is in the half spaces. But even still, he's shown a discipline on and off the ball, along with a intensity that not only helps in offensive transition, where he also provides a goal threat. but he's someone that is strong in the defensive transition.
Laimer is someone that's closer to Goretzka rather than Gravenberch as far as profile goes imo. Laimer will potentially enhance your ability in defensive transitions, and is very adept at leading the wolf pack press sequence after the press sequence is initially triggered by one of the forwards.
So I can see Laimer potentially fitting into Nagelsmann's squad because the aim is to play a proactive attacking brand of football in a compact high block. So to be successful in achieving the desired goal a club like Bayern will have to control the game. And to control a game in a compact high block, the offensive and defensive transitions have to be controlled. And a player like Laimer will potentially provide a fantastic option to control the defensive transitions due to his ability off the ball.
And with the addition of Mazraoui at RB, Bayern have potentially further enhanced their offensive and defensive capabilities due to his ability to provide the inverted fullback threat, overlaps, under laps and the ability to tuck in as a half-back to maintain structure and balance. So along with having progressive fullbacks, midfielders, and potentially also CBs, you also have a GK who is progressive. So someone like Laimer would add to the team and provide a nice balance.