We'll see what happens with KZ the rest of preseason. If this was just a "We don't want Keegan's first NBA action vs AD/LeBron" or if he's actually considering him as the "opener" defender on starting wings. Pretty obvious he's a favorite of Brown. That bench unit looks damn explosive though so I get the idea of balancing your USG and upping the defensive ability of the starters. As long as Keegan is consistently getting 25-28, I could live with him off the bench to start the year.
That said, if you do that, you better start off hot and winning games. Otherwise you're going to get asked very quickly why Keegan is sitting in lieu of a journeyman wing defender.