Does post meeting transcriptions improve over time?

Are the transcriptions that are processed after a meeting has ended (post meeting transcriptions) a one-shot deal or is an initial transcription processed but, as long as the recording is not deleted, does the file get processed again to improve the transcription? 

I'm curious because I work for a higher education institute and we use the transcript file (vtt) for captions when we upload the video to our media server. But, the accuracy can be lacking for those that don't speak English as first language or for those that speak very quickly (or both). So, if the transcripts improve over the first week, for example, we would wait to use the vtt file (or grab a new version).