This is not a decision by Sangoma, this is a RHEL decision - As is mentioned on the main page, this is blacklisted by Redhat and has nothing to do with us!
However, I did think it was a bit unusual, so I did my due diligence and tried to get a HyperV machine working, and gave up after wasting 2 hours just trying to get the VM out of UEFI mode and back into BIOS mode so I could actually boot a machine.
At that point I decided I agreed with Redhat and added an early check to fail, rather than having it fail 15 minutes later when it was doing all its compatibility checks.
If you REALLY REALLY want to, you can remove that check by changing RESULT_FAIL to RESULT_PASS, and edit the distro_upgrade file to remove that check, too, but - honestly - just use the Conversion tool. It’s much faster. 5 minutes vs 30 mins.