Yeah can't denies that this is olympic and it would be more plausible for athletes to be the torch bearier rather than artist. But it's not the first time this happens as other artists like john legend or national artists from the country where the country held Olympics. It's actually almost always happened in recent years and choosing Jin to be torch bearier is not weird as he is the one who currently available in BTS and BTS still have their fame till now. It's more likely france olympic committee who asking their agency, just like when jungkook became the singer for world cup Qatar. Basically it's about who is well know in that years or someone who left big impact in entertainment industry can be chosen as torch bearier to drawing in public attention to the event more.