No he was not. Klint Kubiak was the the Passing Game Coordinator with the Bronco's in 2022 when Jerrod Johnson was the Assistant QB Coach with the Vikings in 2022.Since you seem to know, was Kubiak still an offensive assistant.
Like TK said, if Stroud had been picked by the Panthers then this theory wouldn't have held water.
Once again, in 2020 and 2022 when Klint and Gary were running the Offense with the Vikings, Jerrod was a Offensive Quality Control Coach for the Colts. I think that Jerrod got the job with the Colts, based on what he did with CJ Stroud in the 2019 Elite 11 Camp. So in a way CJ had almost as big a influence on Jerrod Johnson's coaching career, as Jerrod had on CJ Stoud's football career.
You can double check my dates, but I believe that you will find that they are correct. Jerrod had no experience with the Shannahan Offensive System before the Texans hired him as their QB Coach. Very strange don't you think?