When the play-in was first announced, I think it would only include the 8 and 9 seeds, and the winner would advance.
Including the 7 seed seems unfair. Going from the 7 to potentially out of the playoffs altogether is a huge, huge disadvantage. Especially if, like the Pelicans, they finished 2-3 games ahead of the other seeds.
Similarly, the In Season Tournament needs to mean more. The Lakers and Pacers played an extra game with stats that didn't count, and a trophy that kind of doesn't mean anything. I don't think you should guarantee a seed to the IST, but that was an actual game that actually happened. Maybe it's a tiebreaker? A win that cancels out a loss?