Clearly a niciety. That said, it's possible that she did excel in other areas. She's CEO not community wrangler. As a casual user, I had no idea who the CEO even was until recently. Similarly, although I have a username, I couldn't name another user or mod on the entire site. Someone got fired? Ok. Doesn't effect me.
Dude this is Pete Sampras here. One of the best tennis players in the history of ever. He can brag; he's earned the right to brag.
Also, this is a great insight into the mind of a top athlete after his career is over. He talks about what he did right and what he did wrong, and where he'd change things up if he had the chance to do it over again. That's some invaluable insight that can benefit anyone who's just starting or who is in the middle of playing tennis both on a for fun level and on a competition level.
If this was an article written by Linus Torvalds in exactly the same tone, as a letter to his younger self, would you say he was bragging? Or would you be overjoyed that he'd shared some of his struggles so that you could learn from those struggles and maybe avoid them yourself?