No, what I have figured out, it came gradually. Obviously he tried his best to come up with suggestions and ideas for the first 3-4 seasons. Around season 6 he was tired and wanted out. He actually suggested that they should write out Chakotay but they refused.
That's one of the few things I'm happy about. If they had written him out, they would have killed him off, something I really didn't want. They could also have ruined the character in the same disgusting way they destroyed Kes.
Anyway, I can't imagine Voyager without Chakotay, my second favorite character in the show.