Sure, the whole point of the thread was a guessing game. I'm speculating that Apple, had it not been worried with going bankrupt, could have tried to fix code that had grown organically and incoherently over decades.
And that this was a missed opportunity for the whole industry as it's probably not going to happen anytime soon.
In any case this is playing guessing games, what would have happened if Apple wasn't begging for money.
So who knows how System 9, 10… would have turned out.
As for the Longhorn example, part of it did ship, as SQL Server features and some ideas on ReFS.