I think it's that they know the demand is there, but it's not in the volume that it takes to sustain the line (I wish it were, too). So they've cut back on manufacturing to meet the current demand, so it appears that they are super hot sellers.
For example, if they make 200 and the demand is 100 then they have a surplus that doesn't move. But if they make 95 and the demand is 100 then they have a hot market that might grow a bit, and if not then they still aren't stuck.
The point is that the "Look they are sold out at Hasbro Toy Shop so there is your evidence for demand" argument is not entirely valid.
Unfortunately. -grumble-