Philly runs a "WCO" but it's more Air Coryell than anything. It's predominantly shotgun with deep routes. Same goes for Green Bay and Minnesota. They're hybrid WCO schemes. Shannahan and Kubiak run a WCO in name, but their entire offense is based off the zone run and the bootleg off of that (eliminating half a field worth of reads) than any particular passing philosophy. They all have some WCO principals, yes, but they're very far removed from the original thing.
It's like the spread offense in college football. Take Florida for example: look at how fundamentally different the offense was under Spurrier, Zook, and Meyer. Yet, it's never been called anything other than the "spread" there. Furthermore, look at how different the spread is at with Meyer at Florida, compared to Texas Tech under Leach, to Texas under Mack Brown, to the one run at Oklahoma. All are dubbed "spread offense" yet they're all so different that they're not even really comparable.