They might hurry if they think Ms unified platform is a threat to them.
Say Neo release day and date with Scorpio, same performance, but Ms completely nails the platform unification and also brings all the games that have been skipping xbone through this gen, not to mention ramp up BC massively that offers almost all 360 titles as well OG xbone, along side tons of options to play those games with different price points so you can have pretty much a way to play your games every room of your house or everywhere you go?
I think it's on their best interest to get a more powerful box that could take on the higher performance crowd as soon as possible and try to get more people locked into their ecosystem so they might not feel as compelled to go to Scorpio when it's later to the party.
Unless of course sony has something planned about making their platform bigger than the console you play on.
Edit: That doesn't mean Ms will instantly crushes sony or anything like that, but I believe it would be stupid to ignore the threat or the potential a platform that can reach many price points and form factors has.