Dorion would want the draft after the playoffs because his plans for the upcoming season probably heavily hinged on being able to move some of the draft picks for other things.
I'd bet he's pretty much at the "try to acquire Rick Nash and a goalie" stage of Bryan Murray's previous rebuild.
33 overall is worth 33 overall to every team. But once you take a player, that player could be worth something very different to each team depending on where they were on each list. So if our plan was to bundle some draft picks for a good young star from another team, it could end up costing us a lot more if we have to use our picks on prospects at the draft, and then make the trade for that star player months later when the season is over.