Update on the NBA TV package. This thing is about to get messy.

Probably not that messy. My guess is that the NBA creates a fourth package for Amazon to stream while it gets even more media revenue.
That would certainly be the cleanest way to resolve this. Otherwise, lawyers are about to make out like bandits.
Why? WBD had an exclusive right to match any of the packages' offers.
It's like being a restricted free agent. WBD tried to negotiate a new deal, and the NBA thought it wasn't enough.
Other teams (in this case media entitities) made offers and the NBA signed a preliminary agreement.
But WBD had the right to match one of them, which they did, which was the Amazon Prime Video offer.
Nothing was guaranteed to Amazon until WBD had possibly let the five-day matching timeframe pass, which they didn't.