I think a lot of the reason WM's aren't letting them go out the door is because of toy recalls in the recent past. That's been a big thing, and I think it's made many managers gunshy to let something that isn't in the system go, or that's bringing up a code. It used to not be this much of a stone wall when something wasn't in their systems... Now, not so much.
They obviously don't know one item from another. I tried picking up a regular Evolutions set when they weren't in the system yet prior to the launch of the Legacy line, and they gave me the same run-around. I know the manager at my nearest store and explained to her what the deal was, so she let me pick it up at the time, but she said all the toy recalls have caused them to be gunshy about just "pushing it through" the system.
I can believe that. It makes sense.