This is more of an FYI for folks. I put in a SR to get the post-processing behavior of Set-VMHostAuthentication documented.
As detailed, you should plan on a pause after Set-VMHostAuthentication before performing Get-VIAccount & New-VIPermission to configure local permissions on the ESXi host itself. (Not in vCenter.) If it's after a new install, my experience was that a 2.5 - 3 minute wait was necessary. If it the host was recently joined to the Active Directory domain and it's just being rejoined, much less time is needed.
After the pause, plan on retrying Get-VIAccount until it works, as described in the KB article. Once Get-VIAccount starts working properly, Set-VMHostAuthentication will have completed and no further errors should be expected.