The original DF article didn't mention this build lasting the whole console generation. In fact the exact opposite is true. They call out the fact that it's unlikely to last the whole generation here:
https://www.eurogamer.net/articles/digitalfoundry-2015-budget-gaming-pc-guide
I think there's an element of filtering out the past arguments that best suite the current narrative here. The 970 is still more capable than the base consoles today. And while it was far more capable when it launched, and that lead has been significantly been cut into, if you'd bought it back when it launched only a year after the PS4, you'd have got a generation of console beating performance out of it. As I said above, buying at the same time that the new generation of consoles launch is never the best idea from a cost perspective. It may well be possible to see out the whole generation on a top end card. But if you're really that concerned about cost (not everyone is), then better to wait a year or so and buy a more modest one, or buy a lower end card at the start of the gen and then something much better 2-3 years later.