Oh and from that end I agree you can't wait too long, but theres definitely been some voices that think he should be signed because the's done enough down there.
If things weren't the way they are now I'd say he's a perfect candidate to follow the family development path and stay all four years. Drury at 22 is what we want. Given the current climate yes I'd be pulling to sign him after his junior year for sure. After his Sophomore is pushing it, he needs more baking.
Here's what I'll say having really not watched him except at WJC - Drury's pattern has been "one year as a solid 3rd line center finding his way in a league, then one year as a dominant two-way forward" in each league he's played in. AHL might be the next step for him to do that in. Maybe even NHL. Not saying he has "nothing left to prove", but I don't mind giving him that shot now.
As far as "needing more baking", he's 4th in the NCAA in PPG as a sophomore, for a guy who's theoretically not even supposed to be the high-end offensive point producer. Again, not a finished product, but I don't feel like that's the kind of guy where you question trying to sign him as soon as possible to minimize chances of free agency.