There were at least two issues:
- The authorization workflow was broken for many third party integrations (those using HTTP GET instead of HTTP POST for the OAuth code exchange)
- Third party SmartApps were unable to control local devices
Since you were already authenticated, the first item wouldn’t have applied to you and since you are on a hub V1, the second item likely wouldn’t have applied to you either! 
For what it’s worth, it seems there may have been other issues too as some “rule” SmartApps weren’t working properly and Routines were having troubles too.