Skype for Business Outdated Client Issue : TurnAuthUnknownUser

Can anyone shed light on this blog post from yesterday? https://techcommunity.microsoft.com/t5/Skype-for-Business-Blog/Skype-for-Business-Outdated-Client-Issue-TurnAuthUnknownUser/ba-p/39057

I downloaded and installed the attachment into CQD, modified as instructed, but it appears to me that it is listing every desktop client that hits my tenant and suggests we upgrade them all.  It would be useful to know in which client version this TurnAuthUnknownUser issue was fixed. Perhaps the filter for "OC" literally stands for "Outdated Client"?

Thanks