No he really doesn't care about it. That was fairly classic Fed being diplomatic. He'd only care about getting to Jimmy's record of what 125. Number 2 or 3 on list doesn't really interest him at this stage.
I don't know how you can reach that certain a conclusion unless you are Federer yourself.
I mean, he brought the subject up, the interviewer didn't. So obviously he has thought about it, so I conclude that he might care about it to a certain extent, especially the closer and more attainable it seems to him. Whether he absolutely does or not, only he can say. He knows history and what records are on the line. And by the way, Jimmy's record is much less, though still high -109