Thank you for your question.
I have consulted Revit team and confirm that you can import 3D views into 2D views with the original Revit drawings in Revit. However, Revit doesn't support to import dwf file with 3D views.
If you have all dwf files, you can merge views easily with Autodesk Design Review (ADR) by following the below steps:
1. Select all dwf files in explorer.
2. Click the right button and choose "merge" option. 3. Set a name for new dwf file. You can download ADR from
here.
Please let me know if you have any further questions.