Unfortunately there is not much traffic between Canada and Scandinavia, so neither AC nor SK could make the route pay. I doubt we'll see it come back unless FRA and MUC get really clogged up and AC is looking for a fourth STAR hub in Europe [CDG may work better once STAR moves all its carriers into the refurbished T1].

As for your alternatives, I guess it depends upon your overall travel and in which airline program you want to build mileage, and attempt to achieve elite status. Travelling via SK in the US requires hassles in that country. You could go via LHR or FRA on AC, then onto SK/BD or SK/LH. AC has fares in the $450 range+taxes/fees to LHR, and you can get to CPH on a separate STAR ticket from there for less than $200 if the dates are right.

More dates and details will help answer your second question.