Sony owns the market right now and with it's larger userbase developers will continually want to make good games for them. As well, developers picked the PS4 as their preferred console this gen so all the more reason to stay with the PS4 family. (Unlike where the Wii had a very large userbase but wasn't the developers' choice of console last gen)
If the Neo is underpowered compared to the Scorpio, developers will find the middle ground and create games that will work for both but highly unlikely that they'll spend the extra time and resources to maximize to Scorpio's potential, that's just how multiplat games usually are. Also note that Japan highly wont care for the Scorpio so Japanese devs would rather make their games based off the Neo instead.
So MS can boast all they want about Scorpio being the most powerful console, but what good is that if there'll be no games to utilize it? All that extra cost for that extra horsepower may be for nothing.
If the Neo is mcuh weaker, the only way MS can gain momentum from this is if they themselves make a ton of exclusive games (or buy/talk to devs into making exclusive games) that maximize the Scorpio and that it'll be so amazing it'll blow up causing a shift in userbase.
But MS may have save themselves by boasting the power of the Scorpio if that caused Sony to go back to the drawing board to bring out a more powerful Neo equalling the Scorpio. Because then developers that maximize the Neo will also maximize the Scorpio. (Poor NX?...can't say much about NX yet until we have more details). But also Sony is in a better financial position now so not sure if they're up for making a more expensive console again.
Basically, in summary, these 'upgraded games' will only go as far as what the Neo can handle and doesn't matter what the Scorpio has under the hood.
This is just my opinion that has been circling my mind since E3. As usual I doubt my own thoughts so tell me if I'm wrong or if I'm missing something here that makes my point mute.
Cheers! :)