Hi carlton5000,
Thank you for posting in Apple Support Communities. It sounds like you want to know if you will be able to share files between your two MacBook Pros, if they are not running the same release of macOS.
File sharing is not dependent on your version of macOS. However, if you are sharing app specific files, and are using two different versions of the app, you may run into issues. You'd need to work with the app developer to find out if there would be compatibility issues.
You can learn more about file sharing here: Set up file sharing on Mac
If necessary, here's how to contact an app developer: How to contact an app developer
Cheers!