(SpacemanDoug beat me to posting as I was putting this together, but for kicks anyway…)
What I read was additional footage was shot by Spielberg very soon after the TV airing to “upgrade” the movie to a theatrical experience. Obviously, this new footage was not intended to be 4:3, it was shot only intended for theatrical viewing for a wider screen experience. (I’ll let other people state what that exact TR ar was.) So, yeah, it could be said that if nothing else, that new footage was intended to be non-4:3.
Another piece of the puzzle is that it would appear the master film elements for the TV version were lost in a big fire at Universal, so the additional-footage theatrical version is the only version that’s in great shape for modern viewing.
All of this together points to the answer being: the original TV — 4:3 — version is NOT the definitive version, the TR is. And for anyone who wants to adhere to the orig TV version instead, they have to unfortunately settle for resolution in the SD realm. This is why the new 4k disc has a very nice image of the TR, but the orig TV version in that same set looks horrendous (part being the atrocious attempt at AI upscaling).
At least that’s what I’ve gleaned from reading around, but I’m no authority. Maybe someone else will correct what I have above. (Edit: SpacemanDoug has some more detailed info, beat me to posting this)