Good day! Autodesk Revit is being used in labs by Project Lead the Way which is a nonprofit that provides curriculum in computer science, engineering, and biomedical science. I've included their setup links below (in addition to reports that NV6 VMs work well). While we don't have any specific instructions for Autodesk Mudbox at this time, I've included some other links as well that may be useful. I'm a bit limited in how much I'm able to troubleshoot with you as I don't have Revit or Mudbox, but hopefully this will get you pointed in the right direction.
Setup for Autodesk Revit and other similar CAD software (Project Lead the Way)
https://learn.microsoft.com/en-us/azure/lab-services/class-type-pltw
For licensing you can find instructions here, which walks you through installing LMTools (Autodesk Network License Manager).
Setup for SolidWorks CAD
https://learn.microsoft.com/en-us/azure/lab-services/class-type-solidworks
Setup a lab with GPUs
https://learn.microsoft.com/en-us/azure/lab-services/how-to-setup-lab-gpu
Edit: Additionally, the Autodesk forums may be a good resource. It looks like people are successfully using Revit on Azure using the NV6 VMs.