My current expectation are that it works similar to what you do when creating a save game in FM23. The editor files become part of the save. You can create the save game with the edited files and can share the save with me without me needing those edited files. Using FM23 editor files then should be possible. Only thing is that you miss out on data from FM24.
Thinking this through you could technically/potentially end up with a reallife scenario where you can create a real historical database. Just imagine creating a FM23 game which you then load into 24, 25, 26, 27, 28, 29, 30, 31, 32, etc....