Scorpio is the eighth astrological sign in the Zodiac. It spans the 210–240th degree of the zodiac, between 207.25 and 234.75 degree of celestial longitude.
More importantly, the time period is between Oct 23 - Nov 21. And it's probably safe to assume that the new Xbox is going to be released around that time. Hence why Microsoft decided to call it Project "Scorpio".
Did you know this ? Or just realized it like me.