The DirectX runtimes are not being automatically updated with normal Windows 10 updates so yes, if you see that error, it means your DirectX runtimes ARE really outdated. If they weren't, you wouldn't see that message, of course...
You can download those from here:
https://www.microsoft.com/en-us/Download/details.aspx?id=35I'm not sure why I have to fix DirectX 12 in order to install your airport.
DirectX 12 is not the problem here. What you need to fix, which is apparently outdated in your system, is the support for DX9/10/11, which is required by thousands of other apps that use DX9 ( FSX, for example...), so you want to keep it updated for so many more reasons that "just" our airport.
But if you really want to know, the installer needs support for the latest DX9, because it uses a standard library that use DX9 to create .DDS textures on the fly, depending on the resolution you choose in the CYVR installer, and it does it this way to preserve quality, since it re-create textures from their original sources, instead of just "resizing" them, which would result in a loss of quality because of the double lossy compression involved.