My expectation is that you'd hear a lot more about "gated communities", "gatekeeping" etc. than any of the uses of gates that give warm fuzzies. (As a suffix, it's also associated with scandals; but that probably isn't relevant here.)
I was thinking about gated communities earlier today, in fact. We don't have many of them around here.
But where we do have them: At a given time, the gate might be open or closed; passable, or impassable. The presence of a gate is implicit, but the status of that gate is not known without advance knowledge or direct observation. And even when it is closed (even if it defaults to always being closed), there's generally a cromulent way for a person to get that gate to open and then move beyond it. It is designed to be opened and closed.
Gatekeeping: Sure. I've run across a ton of artificial gatekeepers online in my time. I've bypassed countless scores of them. Those are easy: Just ignore them and keep moving.
These aren't examples of the hard-blocking, impassable lava moats that the bot is fond of using "gate" to describe.
In the context of an LLM using "gate" within code: obviously one can always modify the code to bypass the gate, so there is a built-in implicit assumption that the gate isn't "impossible lava". Most readers are able to read between the lines, but you cannot serve everyone.
That's not how the bot uses the word, though -- at least in my experience. The bot uses "gate" to describe a thing that only blocks, and can never open.
Code that never opens is code you can delete. If the bot hasn't deleted dead code, especially given that this is code it recognizes as being dead and documents it as such, it must believe that you plan to use it again someday. That would imply an expectation of the gate opening eventually, even if not immediately.