Pardon me whilst I do some
FACT TREKing on all this. Mostly because most of the sources fans have access to have repeatedly gotten the particulars wrong about the development of the outlines and script, whereas we (
@Harvey and I) have many many if not most of the drafts of it and tracked the changes.
Yes he is talking about the CANON Guardian, in the original TOS episode it's a hexagonal doorway. They are throwing that out, and replacing it with Ellison original script idea. Which was scrapped ONLY due to budget.
"Beckwith is then escorted to the surface of a nearby planet alongside Kirk, with Spock to carry out the
execution by firing squad. Because of the planet's atmosphere, they have to wear
environmental suits. On arriving, they find an ancient civilization and the remains of a city — this was Ellison's "city on the edge of forever". It is inhabited by several 9-foot-tall (2.7 m) men, the Guardians of Forever, who protect an ancient time machine.
[4]"
The firing squad and environmental suits appear only in the Original Treatment dated March 21, 1966. In the Revised Treatment May 13, 1966 all the firing squad stuff is crossed out and Beckwith flees via the transporter. Thereafter it was always Beckwith (and, finally, McCoy) deliberately beaming down. Kirk reports the planet shouldn't have an atmosphere yet it does, so no environment suits.
^^^This revision process is pretty typical. Ellison wrote his first outline very early on...before there was anything but the two pilots to refer to. He got feedback from the
Trek staff on things that didn't fit the planned and developing show format, so out went the firing squad and expensive space suits, etc., and the Revised Treatment reflects this.
You are
correct that Ellison's
original idea was that there were Guardians
plural who resided in the titular City on the Edge of forever atop mountains in the distance. But, just to clarify a fundamental difference, the Vortex was less a device for time travel and more a means of accessing and harnessing the flux lines of time and space, which the First Guardian said was because "only here" did all the pulse lines of forever meet.
The Guardians plural appear in all the story outlines and the "Writers Draft" script.
By the official first draft, the Guardians plural become a single Guardian, "the last of my kind".
At no point in any Ellison draft are the humanoid Guardians actually the time vortex, which is what Carl says he is.
And yet, Carl is not a 3 m statue... so still not the original concept
Even of they had been, it would still not be the original concept, because they were
never "statues"; albeit they were basically immobile except for their faces.
In summary. Carl is in no way shape or form anything any conception of the Guardian(s) that Ellison ever wrote, regardless of what RMB or any other self-proclaimed authority claims.