Reasons this is bullshit:
1) Sony, Ebay, and EB have no incentive to do this. What do they care who ends up with it. Ebay actually would be losing quite a bit of money.
2) It would be extremely difficult to do. EB isn't exactly known for being effeciently run. You think a company where half the stores don't understand their own sales can mount a company wide effort to match preorders with sales on ebay?
3) Legality. While I don't know the exact laws, and it may be different in Canada, once you sell something to somebody else, you no longer control the means of distribution on it. If not outright illegal, this would most definately be borderline.