I liked the idea of it to begin with. I'm a big fan of European soccer and so the idea of in-season tournaments is something familiar to me, though they do it a bit differently - they have separate games for the tournaments because there are a few of them (e.g. in the UK they have the FA Cup, the Carabao Cup, not to mention the inter-league transcontinental cups like the Champions League and Europa Cup) and so the teams have a bigger squad to reflect that. They tend to play their second XI for the lesser cups or games against lesser opposition and the first XI for the big games, because their Cups are open to all teams in their league, not just the top league - you have teams from lower divisions (aka the G-League) competing with the likes of Liverpool and Manchester City so you get Cinderella stories like you do with the NCAA tournament.
With the NBA Cup obviously workload would be an issue with additional games or including G-league teams so the whole doubling up of regular season games by rebranding some of them as in season games, and then having to figure out which games would be the knockout ones that would also double up as regular season games was confusing. But I think it's added some excitement to some games that would otherwise just be ho hum.
Even the points differential thing added some spice to the games last night as we tried to work out how many points each team needed to win by to make the QFs. Again, I'm probably more used to points differentials being used to work out which teams progress because of being a soccer fan, but it might not be for everyone. Personally I have no problem with watching blowouts, and little patience for players on the losing team complaining about "disrespect" - its a professional league where people are getting paid millions, not AAU or college, if you don't want to get blown out then play better
Maybe they can tweak a few things, and I'm sure they will - to me the biggest tweak they could make to make it really meaningful is to make it so that the winner is guaranteed at least a play in berth in the actual playoffs. That would make it really meaningful. But conceptually I think it's going to be a winner.