To my knowledge Bunkai was already a part of karate as was Kyusho but when karate was introduced into the schoolsystem (highschools) these were taken out because the karate introduced there was meant as a fysical excercise rather than a tool to learn fighting
Choki, hen he started teaching, wasn't even a karateka but a brawler, he learned karate from watching it through the fence
Before the intro on the highschools Karate was still a civil defence art, after introduction it was made into the same kind of art as Iaido and Kyudo a mental and fysical excersise

It was Choki who showed Konishi and Ohtsuka the bunkai ( because of this they started experimenting with Kumite forms)