That is the right stuff for that door jam. The jam has a slot cut in it and strip as a stiff spline that slides into the slot.
With a 3 or 4" drywall spatula you would be able to get behind it on the outside and pry it out toward the door.
The problem is , you can damage it if you are not real careful, then there is no talking to the contractor.
I have the same thing and I adjust it to fit the door every fall and right now I can see light for the whole bottom half of the door.
This is what you have.