Yes, sometimes novelization tie-ins will tighten up those little details often left by the filmed version. And a lot of times, they are written based on the uncut screenplay. (Sulu's promotion to Captain, and his soon to be command of the Excelsior was another scene that sadly did not make it to screen...largely because of Shatner's shenanigans.) It is quite possible that a scene regarding Khan's total recall of Chekov may have had a bit more detail in the uncut version of the script, but such exposition would've been a waste of a few good seconds of screen time, and would've tasked the audience (especially those in the know of Space Seed) to search their memories, wondering, "Did Khan meet Chekov?" (Or, for those who did have total recall of Space Seed, they would likely have said: "Wait a minute...that never happened!" (Had Wrath of Khan been shot today, as is, with the existence of DVD players and Blu-Rays, Khan's mysterious total recall would've been booed by the audience.) It would've detracted further from the enjoyment of the movie, far more than Khan's mysterious recollection of everyone's favorite "Russian Inwention".
But, as is often said: "If it didn't happen on screen, it didn't happen." A lot of times, that is a dogma I don't like to buy either, as I find it is subject to the double standards of fanaticism. In this case, though, it's pretty clear cut...Chekov never even appeared until later in the series, so as far as I'm concerned, he wasn't even a member of the crew, and Khan never met him face to face on screen in Space Seed. It's a goof. But that is simply my take. The story was written as it was in the time that it was written.... and it sold....playing upon the ignorance of the audience, but it sold. (And people accuse the JJ movies of lesser crimes with greater vitriol.) Makes me glad I am no longer a fan of anything....I don't wanna be counted in with such people.
Fictional a character though Kirk may be....I still don't buy the "hero must die in a blaze of glory" mandate. The only realism that can be applied to Kirk is that he is a human being, no more or less than you or I, subject to the same frailties and ignominies any of us can face at any moment. Too many times, there's been this "shield of posterity" that miraculously protects "fictional heroes". I used to believe in that, once upon a time. But, as I've grown up, I've come to the realization that Kirk can face as unjust an end as you or I...at any given moment. It is not a matter of "realism" that Kirk must die in a blaze of glory. That is fanatical dogma.
Kirk died doing what he did best, making a difference. That (in my personal opinion) is what really matters. That he died "bridge on the Captain" (as Shatner often jokes) in no way detracts from the fact that he died heroically. And as you acknowledge, yes, he did die heroically.
In the original script for Generations, Kirk was simply supposed to be shot in the back by Soran. That would've been just as "realistic" a demise for him as any. But, unfortunately, because of the dogmatic nature of fanaticals, that didn't test well....so Moore had to re-write the ending so that Kirk at least died a somewhat more heroic death.
Technically, Kirk died two heroic deaths.... The death that history would've recorded in the latter 23rd century when he was (according to what the crew could surmise) blown out into space on the Enterprise B. The death he actually suffered is the one Picard witnessed. I'd dare say that's quite fitting for someone of Kirk's "stature" if you wanna get down to the brass tacks of it.
