This makes sense. I doubt he will be given a guaranteed contract, but I don't see any reason not to invite him to the summer league and camp with the chance to make the team.
We know they are going to need some more size next season, and we also have a lot of spots at the end of the roster to fill. So now is as good a time as any to give him a shot to prove he belongs. If he can't make the team this year, I am not sure he ever would, so there is no reason to hold onto his rights if he doesn't make it.
And more importantly, I don't think he is going to get a whole lot better playing in Europe at this point. It is such a different game for big men, that getting him over here, testing him in a US system, against US big men, and with US coaching is the only way we will know if he will ever be an NBA player.