Probably not. Not when he's still one of the youngest (if not THE youngest) and least experienced guys on the squad. This is a veteran laden team and JV was supposed to be coming off the bench until the other dude got hurt. It's a long way from dominating the U19 tourney to starting in the Olympics. I'd bet that especially after having lost the Eurobasket on their home court and having to go to the last ditch qualifier they have a ton of pressure on them to medal in London. Totally natural for the coach to go with the vets.
It really is, and people need to have some lower expectations with this kid. He'll be good, but he's going to have a lot of bad games this year. This is a great chance for him to play at a higher level than he ever has, and right before making the jump to the NBA. Given that by all accounts he's a workhorse, this should motivate him to work even harder, even in the time before next season. I'm sure the coach for the Lithuanian team would like to play him more if he earns it, and it makes sense to play vets more on this stage. I'm sure they even know the value of getting him this experience now, much like Anthony Davis with team USA, who will probably barely play if at all, just to be in this atmosphere and see what the best players in the world are like. It'll all pay off down the road.