I was told the same thing by a local Ford dealership. Likely Ford's way of selling us a $600 intake rather than a $5 gasket.
Probably so. However, when I swapped out my manifold, upon further inspection, the surface between the crossover pipe and the manifold wasnt really how it appeared before I started the job (which I thought was just a typical mating surface between a plastic and aluminum part). It really isn't meant to be repaired. I say this because, it's not like a gasket gave way age & use. The plastic surface on the manifold port actually deteriorated and broke away. That would never be repairable with a new gasket.
There is only one way to go to fix this correctly. Order the original Ford equipment manifold from Tousley Ford. Their prices are seriously insane compared to the local "Stealer".
I did a side-by-side comparison between a Dorman manifold and the OEM Ford. They are not even in the same stratosphere in terms of quality. Go Ford OEM (please)
Depending upon your production date, you will either need (or not need) a replacement alternator bracket. Tousley will tell you.
Parts: 1L2Z9424FA (Manifold - $254.31)
YL3Z-9439-BA (Manifold Gaskets - $15.83 each)
F1VY-8255-AA (Thermostat o-ring)
Chances are, you do not need the alternator bracket or the longer thermostat housing bolts. If you did, purchase them separately as opposed to the manifold kit (1L2Z-9424-AA) which is more expensive than the sum of the parts. "Bear" from Tousley (awesome guy) and I had a laugh about this. It seems that one of the parts in the manifold kit was labled "instruction sheet" and that must have accounted for the $50+ difference between the kit and its components. Go Ford!
Best of luck