Neat idea. I'm sure this will solve some friction for the neuroscientists/mathematicians out there with ~20+ windows open.
Personally (as someone with ADHD), this would just relentlessly grind my gears. My thoughts are unpredictable by nature and so I value the "reliability" of knowing my chrome is two alt+tabs away, etc.
If an algorithm started messing with this and changing throughout the day... Damn, I'd go crazy.