As someone born in the 1980s, I appreciated the look at how the Cosmos and the NASL formed and imploded. The Sounders don't make much of an appearance (their logo flashes on the screen. The Whitecaps victory in 1979 gets some screen time. (Aside: I love the old NASL shootout format so much more than shots from the spot.)
ESPN Classic has aired it. The link is to Netflix, which says it will be streaming it starting June 1.
I can't verify any of the historical claims (like that the Cosmos' loss and the U.S. not getting the '84 World Cup led to the demise of the NASL), and I'd be interested in hearing anyone else's opinions.