Proxy Support for AutoPilot
Windows AutoPilot should prompt for proxy configuration if after establishing a connection there is still no internet access. This would allow enrolling AutoPilot devices on the corporate network and use hybrid join.
I think this feature should be implemented really quick as there are a lot of enterprises waiting for that.
Chances are higher you will migrate faster to a non-proxied environment in your company, than waiting for this feature.
If your IT uses a proxy to keep track "who connects to which external hostnames", then I guess this little party will be soon over, once the world will move to TLS1.3 with ESNI, and your corp office LAN will transform into a simple Starbucks Internet connection.