Hey, @InspiredCargo77!
Just fired up MSFS (with WU8 installed) and do a quick tour of PHOG with the Northern Sky Studios airport addon. This is what I saw:
Departing Runway 5
Overflight
So - my guess is that the issue isn’t an incompatibility with WU8 and the Airport. I would try moving (not deleting) your Community folder out of the MSFS tree, creating a blank Community folder in its place, and moving only the PHOG Airport back in. Start up the sim, load up PHOG, and see if the pink textures remain. If they don’t, there’s a possibility that two or more things from other sceneries could have conflicting GUIDs (a (supposed to be) unique identifier associated with things in the sim.)
Would you mind trying that for me please? Will be out of the house again until probably 0830Z. Please let me know if you’re still running into issues though. I will do my best to help you get them fixed.