Whenever and whatever Apple releases I hope they get wifi right this time. Both my Mac Mini and 2015 rMBP drop connection constantly. Support tried to tell me its my network, except all my other devices (inc iPhone and iPad) keep the connection just fine. It's taken the shine off two otherwise wonderful machines.
I had that problem on my 2012 13" rMBP. Dropped the wi-fi frequently, but no other device (Phone, iPad, Windows laptop) did it. Unfortunately I kind of thought of it was a Mac problem, unlikely to change...
Did your Macs still remain connected to WiFi but have no internet connection? Or did they drop the WiFi connection altogether?