Hi MD, No one was necessarily "in the loop" and the new version info just became available over the last 24 hours. tt2 posted an update and in my case - while I saw that - I was presented the normal update prompt when I launched iTunes today. I apologize that I am not specifically familiar with Audacity though I use similar software which in my case as well - was that files created with my software outside of iTunes were the ones impacted. In your case, since you have some concerns, perhaps proceed with caution.
Perhaps wait a little while and see if any others report issues. So far, I've seen positive posts. If you plan to update, be ready to roll back again if needed. If you have more than one PC, try one first. If you are in good shape now, no need to rush. If you follow the discussions, here:
https://discussions.apple.com/search?page=1&q=AAC%20789&content=filterDiscussions&time=month
you should be able to see what all are saying.
Apple has also made the new version available on their Download page: https://www.apple.com/itunes/download/
Think about what's best for you. Since your use of iTunes is part of your profession, definitely proceed only when you are confident and when you have plenty of time before next jobs. Good luck!