Meyer and producer Harve Bennett sat down and watched the entire series though. That’s how they got the idea to revisit Khan.
Nemesis director Stuart Baird didn’t know Trek either, and allegedly thought Geordi was an alien. Levar was supposed to have been upset about that.
JEDIT: Baird’s lack of Trek experience was worse than I thought, if this article is on the level.
http://www.denofgeek.com/us/movies/star-trek/248258/star-trek-nemesis-what-went-wrong