As announced during a live stream on Periscope, there'll be a global broadcast on the official Facebook page on August 31st. More information about NBA 2K18 will be revealed during the event - which is named "Run the Neighborhood" - including details on MyCAREER.
The hashtag #RunTheNeighborhood is also being promoted. It's obviously the name of the event, but given that MyCAREER info is specifically mentioned, I'm guessing the name of the event and the hashtag have a connection with this year's story. Perhaps we're going to start out as a streetballer, not completely unlike what NBA Live 18 is doing with The One.