Not exactly. It was a set of macros, yes, but the goal was an improved editor, not a standardized interface. Later there were multiple ports which shared many things in common, such as key bindings, on–line help, etc.

No, it was a standardized interface. Guy Steele talked about going around the office collecting keybindings from multiple people and distilling them down into a standard set.

But not from users of multiple editors. They were all users of TECO who had written their own macros to add similar features.

I'm not sure where you're going with this. A bunch of people wrote macros for TECO. Moon and Steele collected them and standardized them. The set of standardized macros is Emacs.

Thus, Emacs originally was a set of macros to standardize key bindings across multiple editors that existed at the time, exactly as GP said.