This is why you are missing Collins arguement.
PS4 Pro is an iteration of the PS4. It will play the same games, but run/look better.
Scorpio WILL be the next gen Xbox. He believe (as do I) that MS is ditching the Xbox one, it is carrying far too much baggage and always will. It is only a matter of time before the Xbox one support is dropped completely. They did it to the OG Xbox and they can do it again.
Xbox S + Playstation Pro, play the same games as their namesake's, just better.
Scorpio will be a completely new platform.
That is the difference.
Scorpio isn't their next generation console, it is still tied with this generation and the Xbox One. It can't have exclusive games, unless Microsoft completely backpedals on what they're saying, which isn't foreign to them I suppose.