I stand corrected and I completely confirm this to be true. Not just Outrage, but Thrash and Petal Blizzard seem to cause confusion if interrupted now.I've experienced myself an exception of this speculation you bring here. It would seem that if the Outrage is interrupted after it gets off, the user can end up becoming confused out of exhaustion. This had a pretty critical change of outcome in a switch in I did on a nuzlocke run, so I remember this quite well.
I experienced it myself by fighting some Wi-Fi trainers; one had a Pinsir that was spamming Thrash, so I switched in Aegislash and caused confusion. The other one was a Vileplume (lol) and I switched in my Sap Sipper Gogoat; it caused confusion.