No, John Smith would have won in 97 had he lived, the idea that old Labour was the problem and New Labour had to emerge to be credible to capture the middle ground is a myth, and if you accept Smith could have won in 97, then all you see is New Labour pissing on huge majorities as we lost voters in every subsequent election, until New Labour's vacuousness was exposed for all to see and they ran out of road.
For those that say Corbyn can't win in 2020, you have to ask if any of the other three candidates could, they might hold on to what they've got as the Tories fuck up and maybe the odd seat captured here and there, but Scotland won't come back under Kendal, Cooper or Burnham, seen though that prism Corbyn is not the risk some people might think.