Guessaaa:

It seems you are all out on getting this J seat. You may not have had the history of this problem since you only joined in May, but kudos to you for finding this old thread!

Most FT'ers here (based on my observations) would not book an award ticket like yours when the most important leg is not confirmed in J (i.e., D). It is just too much of a crapshoot. My gf was very fortunate to have gotten a courteous and helpful (but not-following-the-new-policy) gate agent and got her seat. In your situation, the situation may be even worse because, as I understand, YYZ-LHR is very much a paying J route.

Just as a point of clarification, assuming you book such a ticket - you can always call back and if D opens up on the flight you are confirmed only in W, you can get AP to change that for free.