I probably shouldn't admit this, but I've only seen three or four episodes of TAS and am not very well-versed in it.
In my defense, TAS had been declared off-limits at the point I started writing Trek books so there was never any incentive to familiarize myself with it . . . ..
I think I discovered TAS (which was still in first run at the time) only a matter of weeks after I discovered TOS, so to 5-year-old me, there was just one show that was sometimes live-action in the evenings and sometimes a cartoon on Saturday mornings. My first Trek book was Foster's Star Trek Log Three. So I've always seen TAS as an inseparable part of the whole. I think the first time I got any indication that it wasn't universally seen that way was when The Star Trek Compendium came out and made no mention of it (though they added a cursory TAS section to the second edition a few years later).