Is the new Flight Simulator not using the faster DX12… just curious as my MSI Afterburner is showing D3D11 fps…

Yep. Not ported yet. No official statement yet. I would suggest to report/question it to: https://flightsimulator.zendesk.com/hc/en-us/requests/new

This was discussed a lot and I think/hope/wish they got it and will introduce this with VR/Xbox releases later this year.