I don't like it. Personally, I don't find the games to be too long anyway. They don't even give any rationale for trying this out. How about tossing out a reason for trying this, NBA.
I think the length of NBA games is about right. It's not like a 3.5 hour boring baseball game.
If it's about cumulative minutes these guys rack up, then reduce the number of games. You could keep the season just as long, but have, say, ten fewer games. You could reduce the number of back to backs that way, and perhaps squeeze in a few more practices, of which there are too few during the season. Might make for a better product while reducing cumulative minutes.
Anyway, I don't want four fewer minutes a game. At. All.