The BRS system has been used at many speeds both above and below 133 kts IAS and never failed except for a 200+kt crash dive resulting from an icing incident. An engine failure does not result in a crash dive, but rather, results in a glide.
Cruise speed range (green arc): 59-149 KIAS
Vno: 150 KIAS
Smooth air cruise speed range (yellow arc): 150-199 KIAS
Max speed (red line), Vne: 200 KIAS
So where is the value of the safety system if it cannot be deployed up to and including Vne?