When did sipdir.online.lync.com and webdir.online.lync.com stop responding?

Microsoft is still asking for CNAMES to 'webdir.online.lync.com' and 'sipdir.online.lync.com' but neither response anymore including to the 443 and 5061 ports.

Googling and not finding anything about the requirement being removed but the 'check health' for DNS under settings still looks for these.

any ideas? Not a huge deal as everything works but wondering if they are still needed?

I only found this 1-year-old article which, among other things, mentions "Remove Skype for Business DNS records if the SIP domain is no longer used. Thanks