This is a great way for him to get more publicity and attention. He defiantly has already made his decision. Popularity is a big part of an athelete's job and this is one way for him to get some positive publicity. He can get more endorsements, which is an important part of extending the money he makes.
Yes Kevin Durant is just causing drama. I don't know why he needs to announce which team he will play for on TV. He should just go the old fashioned way and announce it after he has signed his contract. He is using this to try to receive a bigger contract.
Professional athletes often enjoy creating lots of news and drama surrounding their decisions when it comes to picking teams to play on. Many athletes often find creative ways to announce their team choices to encourage the rumor mills in the media. This creates a lot of attention with fans to see which team a player is going to sign with. Therefore, it is highly likely that Kevin Durant is just creating drama by announcing his team pick on The Players Tribune.
Kevin Durant's decision to communicate through The Players' Tribune is not about creating drama. Several players such as Hassan Whiteside, Kevin Love and Lance Thomas to name just a few, have in the past made important announcements through The Players' Tribune. Founded by Derek Jeter, The Players Tribune is believed to be an important medium of communication for athletes with their fans.