Like I said, I don't think it would hurt him to go back, I just don't think keeping him is harming him. In fact, I think it's best.
And I know Detroit is known as a team that doesn't rush their prospects, but when they were in the Oilers' situation (ie. a bad team getting high picks in the draft), they had no problem with them going straight to the NHL. The last time they had a pick higher than 20 was 1990 with Keith Primeau. He played in the NHL the following season. In 86, they took Murphy 1st overall and started him in the NHL. He went to the minors after 5 games, but he started in the NHL. And of course, Steve Yzerman made the jump right away after going 4th overall in '83.
Detroit's "rule" of letting players develop has just as much to do with them 1) not needing them because they're already a good team, and 2) they rarely get players in the draft with the kind of pedigree that would allow them to make the jump than it does with any kind of team philosophy.