I’m reminded of that time 10-years ago when Apple rewrote parts of its networking code (discovery/mDNSResponder), and it caused so many issues they had to revert the code.
https://news.ycombinator.com/item?id=9026192
https://www.macrumors.com/2015/06/30/apple-releases-os-x-10-...
Unless I'm mixing it up, I still remember this as the infamous "wifi update"
They’re possibly dropping a protocol they’ve been saying they’d drop for years, and tightening connection validation.
This is nothing like the mDNS stuff.