As an early adopter of actions I remember that it was wildly different in its first version (beta perhaps?) than it is today. I have no source to back this up because it was too long ago, but I feel like I remember hearing at the time that the reason it changed so much was _in part_ because of the ADO presence. So I think you're right that the vision was there before hand, but what we have today is very much because of the influence of ADO (in particular, the mandate to run actions _on_ Azure, IIRC).