This is a bit needlessly dismissive.I doubt anyone I actually game with would know what you meant by player agency. But sure ... it's widely accepted, well known, not at all controversial except for dozens of pages trying to explain to you why it's not. Just declare that it's clear and it is!
I do think that most people know what is meant by "player agency," including the people you game with, and I also bet that you do know what I mean. You even explained it perfectly yourself in the other thread: "it's what the player does."
This is also what I mean and how I am using it. The problem is that you apply your own definition inconsistently across TTRPGs and don't look outside of direct player control of the character in the fiction. It claims that things like invoking fate points in Fate aren't a form of player agency, but that's demonstrably false by your own definition because it's what the player can do when playing the game!
That's my issue. And that is hardly controversial, groundbreaking, or difficult to understand.