If they are going to take this seriously I would prefer to see it be a "best of the rest" type tournament, and include the teams that do not make the playoffs once the field is determined. Could still be single elimination, and maybe the final 4 of the cup get an advantage in the draft somehow, to level out competition in the tournament. Or just stop it altogether and move on to the next inane idea to try to bolster flagging fan interest. Maybe if they put some work into making the overall a better product rather than just trying to wring every last drop of blood from that stone, you know by putting those resources into training or review programs for more consistent officiating or figuring out a better draft lottery strategy than just giving the league darlings the top picks.
Frankly I would love to see how hard the current star crop struggles if held to the officiating standards of the 80's, when you got called for a carry for 90% of the dribbling that happens today. It takes a LOT more skill to control the ball when you can't just pick it up, take 3 steps, dribble again, then take 5 steps through traffic while bowling over the defender on the way to the rim, and getting the favorable foul call. Or at least just be consistent on what actually gets called and what constitutes a foul and which 5 steps you are going to allow. Fix that **** first, then worry about how to generate interest in fake accolades like the NBA Cup. Fitting though that they name it for a piece of equipment used to cradle your balls, because it sure comes across as a full-on fondle for the league.