RJ used his abundant wordbuilding notes in one of three ways: as mini-infodumps, most of them rather off-handed, to set up (often way ahead of time) future plot developments, eg: reveal a "neat" OP trick because it will play out two-three books later. A second way was to throw WB details at us in support of a theme. A lot of the male/female details of the OP were thrown at us for that. They didn't really had a plot purpose (there's very little male/female OP interaction in the series) but to support the various gender complementarity/opposition themes. A third way he used his world building details were as "easter eggs". He knew a fair portion of his readers were very very interested in those, and when it made dramatic sense to include a chunk here or there, RJ indulged us, on occasion.

What RJ never did was the big infodumps "reveals". He always preferred to give us answers in Q&A than to clutter his scenes with contrived extraneous information.

Brandon seems to take the "it's too good to leave out" road. That might please the readers who are reading the last books in the hope of filling the holes in some imaginary "role playing" rulebook about the OP or other tricks (and historical details etc.), but so far it leads to rather clunky and unnatural scenes where the POV character spells out out of context (and character) information that is perfectly obvious to him/her and that they would never have spared a thought on, realistically. Indeed, that ends up sounding like excerpts from the big DM's guide. RJ stayed away from that sort of thing like the plague, even favoured starving us for info. It's very hard to believe he would have done otherwise just because it's the last book. To him these were details he might use if there was a dramatic purpose for, never things that needed to be revealed before the end... He had the Encyclopedia slated for that sort of thing.