He didn't go back to tweak minor stuff about gateways to TAR and co. That had little impact on the story and bothers mostly the OP geeks. The one "change" RJ made is that later in the series he re used the EOTW travelling style of the prologue and turned that into the True Power way of Travelling, unique to SH and Moridin. Rand's gateway to TAR, or to TG, wasn't changed when he made that choice, perhaps by mistake (that RJ refined something in one place and forgot previous instances that would have needed a tweak is not unique - it happened to him a few times). The whole end sequence is a bit incoherent in the light of the later series, but it can be excused as Rand himself not understanding what he was doing and the 3P limited POV showing the same lack of coherence.

For the rest... he changed his mind about a limitation of the warder bond that he removed later. Originally he had "The bonding does not tell her how far he is, though, nor in what direction." That bit in the glossary got removed from later editions. That's one change to the series' "mechanics", that impacted the plot and needed to be changed.

Then, changes of mind about the story. Originally in TDR, Perrin had no sisters. After he wrote TSR and killed his whole family, RJ changed the line in TDR (he tells Min something like "you remind me of my sisters" instead of something like "I don't have any sister, but I see you as one".

At some point he thought he might want to get back some day to Tom's "best knives" that were "very special indeed", which he lost at Shadar Logoth originally and so couldn't use against the fade in Whitebridge.

He changed the Shadar Logoth fight in the more recent edition (fairly recent, it's one of those "late changes" he made), now Tom moans about losing his "second best knives" when fighting the Trollocs.

He also changed the timeline of the darkening of the Ways after EOTW (correcting a mistake or reflecting a change in his concept of their darkening? We don't know). In 1990 it was after the TW, later he moved that to after the WoHY and made the change in EOTW too.

In TGH, he had Siuan say "I am the fifth in a row raised to the Amyrlin Seat from the Blue." That got changed after he introduced the story of Sierin Vayu (the third of the five, a Gray). Now TGH has "Four of the last five women raised to Amyrlin Seat have come from the Blue."

Basically, what I was saying is that in Kari's case the context that it happened in an early book isn't relevant, because even if RJ had different ideas back then, the limitations to what Shai'tan can and can't do to souls is een more relevant now and nothing "minor", so now it has to be looked at in the light of what he told us later (in Q&A, not distorted by the POV traps and incomplete knowledge of the characters) about the limitations on "soul catching", and fit with that, or else we can assume RJ would have made changes, if he intended to ever go back to the fact Kari wasn't an illusion.

We know the DO has only a small window of opportunity to catch a soul, Kari's been dead for over a decade and the Shadow found out the boys only months before the confrontation that ends EOTW (and Ishamael learned which one of the three was the one very late in the novel. That wouldn't be the case if Kari al'Thor was a DF) . I don't think RJ thought that Kari's soul was truly kept by Shai'tan when he wrote EOTW, but even if he did, by the rules he introduced later he would have discarded that and said she was an illusion, or else go change the EOTW scene so it worked with a real Kari, like he gave Perrin sisters, changed which knives Tom lost, tweaked the warder bond mechanics because he wanted the AS to locate their warders after all. Etc.

As he never explained that TAR sequence, it needs no change, unless Kari was "real".