I'm not too sure that's gonna happen, and if it did, I don't know how much good it'd be to Sammich. Don't get me wrong, he's raw as , but his problems are much less on the basketball side of things, and more on the mental road - his drive, motor, passion and on-court demeanor all can use a lot of work. Demoting him (even if it isn't a demotion, it'll look like one after thinking he'd be playing with the "grown up" team) simply to have him dominate G-L compe ion isn't, IMO, as valuable as playing him maybe 5-10m a night with the Spurs in garbage time or 3rd quarter, but having him build chemistry with his teammates, be there at every practice, and overall just work on the go on other things, like most players do during the season.
Play him 10-15 as bench PF, and maybe throw him a starting bone about 20 games in, see how he fares against real compe ion. It's also a humbling experience - at some point, you have to "hit the wall" and experience being the least talented player on the court, learn how to role-play, work as a cog in the machine. Luka ain't learning that by posting up G-Leaguers and having an offense catered to him, tbh.