Netflix on a plane? I have never seen that. Which onboard wifi allows that? Perhaps you are thinking of movies delivered via wifi, but the content is streamed from the plane itself.
Qantas has been able to do Netflix/Youtube/whatever on a plane with free wifi for several years. I'm not talking about onboard entertainment, which is a separate thing with a separate app (which is, on the domestic flights where free wifi is offered, largely obsolete at this point). It's not without momentary buffering issues, and I will tend to download things in advance for that reason, but 99% of the time it's pretty good.
I’ve been able to stream video on an Air Canada flight from Vancouver to London, afaik it’s the same GoGo satellite service that seemingly everyone else has.