2 things.
1. Let's see if she still does friendly, fawning ESPN. I think she will. Because I can imagine the network saying "uh, that's Chris Evert out there asking her questions, not a journalist, and we will be doing post-match interviews." If she snubs the network televising and promoting the event and Osaka, it'll be more principled in a sense, but it'll start pissing off a network that pays good money for the matches and that interview.
2. She's really thumbing her nose at the WTA and the French Open - and her fellow competitors - more than the media. Press conferences serve many functions, including to promote other players on tour who might be the next opponent, etc. Once upon a time, five years ago, Naomi Osaka was likely gushed about by her opponents.
Her fellow competitors can't just opt out, either; they're not making $50 million in endorsements. Not that she needs to care what any of them, or really anyone at all, think - she's rich, she's good, she's perfectly entitled to her approach - but the media literally has an outlet to complain or accuse however it pleases whether Osaka talks or not. It's the event and the competitors that have to deal with it. They can't say "I just gotta laugh." They don't have the money to do that.
And maybe Osaka has thought it through but, she gets into the second week she almost certainly will have opponents who are asked about this, and will have to answer. There's going to be a presser after the semis where, say, Barty is asked about it, and that's a story. Osaka's mental health will be in the news for a fortnight.