That's a legit question but I don't think it would necessarily been true. The Cavs weren't even clicking at all for the first half of the 2016 Finals, J.R. Smith was meh and Kevin Love played like dogshyt all series.
If they ran it back then maybe Steph/Klay play better the next time, but maybe Draymond plays worse. Harrison Barnes might play better or he might not. Livingston and Barbosa low-key had great series in 2016 that they might not replicate, and Iggy was only getting older.
In order to beat the Cavs, the Warriors needed Harrison Barnes to play like the borderline all-star a lot of people thought he was, the shyt that got him signing a 4-year $100 million contact after Year 4 in the league. Not sure if he was going to do that. But the thing is, any all-star in Barnes's place could have been enough. KD only had to play as good as an all-star to take them to the title.