Well we have recent history to test this theory. How did the 2005, 2006, and 2007 draft classes fare?
2007 was a little weak.....was that because some players got lost in the shuffle as 15-16 year olds on their teams in 2004-05? At that age 90% of players aren't making an impact (or even playing) anyway, so it's hard to say.
Beyond that, I had a big long post written out that said a whole lot of nothing. The 2005 draft (the easiest to compare) had a ton of CHL players drafted, but a pretty high percent busted. But from what I've gathered, it wasn't due to NHL caliber prospects being returned and taking away ice time.
Gilbert Brule has been an NHL bust, but no high-end players were returned to his WHL team during the lockout. Same story with Benoit Pouliot. And Ryan O'Marra. And Alex Bourret. And Kenndal McArdle. Jakub Kindl and Matt Lashoff had Mike Richards return to Kitchener, but they're defensemen so that wouldn't have affected their ice time.
I didn't go through the later rounds, I skimmed over the 2nd and glanced at the 3rd, but there isn't going to be much conclusive evidence from those rounds anyway. But from what I've found, the lockout didn't have a ton of influence over the 2005 draft class, at least the 1st round.
As you get into 2006 it becomes a little harder to gauge without actually being in those towns watching those players actually play. They were 16 or 17 in 2004-05 so they most likely wouldn't have had a big role on their team anyway. But looking over 2006, the first round CHL busts (Sheppard, Sanguinetti, Wishart, Corrente) had 0 players returned to their teams in 2004-05.
So it's hard to say how much players that would normally be in the NHL returning to their CHL team affected younger players. It just doesn't look like it was all that common. But then the question becomes, was it not that common in the first round or two, because the players that were affected by it ended up dropping into the later rounds?
20 Team Dynasty (points per) - G (25, 50 for defense) A (25) PIM (3) +/- (5) PPG (15) SHG (25) OTG (15) GWG (25) HTr (50) SOW (75) HIT (1) BLK (2) Use actual NHL salary
F: Malkin, Tavares, P. Kane, Neal, Nash, Okposo, Moulson, Ott, Whitney, Iginla, Pouliot, Garbutt, M. Martin, Stajan, Raffl, Klinkhammer, Clune
D: Green, Ekman-Larsson, Bogosian, Gudas, Stone, Oduya, Ranger
G: Anderson, Lehner
Farm: Grimaldi, Gaudreau, Hurley, Hartikainen, Stransky, Fast, Tarasov, Petrov, Kosov, Kujawinski, Maidens, Nurse, Ceci, Donovan, Ekholm, Thrower, Kichton, Borowiecki, Marchenko, Poulin, Nilsson, Andersen