Looks like the Microsoft technote you shared is what Microsoft Support is going to. Got update that Microsoft Support is evaluating the situation as there's an internal cases related to this open by numerous customers worldwide. Will know more in the coming days.
On the side, we're evaluating the application of new registry setting with Security Team, if al party agrees we'll apply it.
Will get back soon.
Microsoft came back updating Exchange to CU11, did some testing (attached) and confirmed everything wtih AutoDiscover and EWS working fine. However, restore still failing with same issue.
Will see what VERITAS come up with, we'd open case.
Get back soon.
