I just remembered one of the perks of my occupation - I currently have online access to all service manuals for every Ford model produced from 1994 to current.
This is the layout diagram for a 2018 FiST driver seat harness (note that they did not update the visual representation of the body harness to seat harness connector to the smaller one):
Looking through the connector face and pinout diagrams for the different system connectors on the 2018 seat harness reveals that they are identical to 2014-2015 harnesses. So, it appears that for the purposes of swapping seats, that body harness to seat harness connector is the only difference, as I suspected. The wire colors are also identical as well. So, to answer your question,
yes - it appears that you simply need to swap the seat harnesses and you're golden.
You might have a loose connector on the new seats after swapping harnesses. That would be for the seat heaters.
Please let me know if you do, because if so I will need to include the appropriate pigtail in my retrofit harnesses for people that must swap their seat harnesses for their Recaro swap. I will not run into this problem for my personal install, since I am not installing Recaros, but seat heaters into base seats and making them work with the OEM system.
I was also have the pinout for the updated body harness connection since you've inspired me to go looking: