From what I have read the franchise corruption issue occurs when the game runs out of available coaches being generated for CPU controlled teams to sign. The pool of coaches dries up and the save file then corrupts and you can’t advance.
To be clear this is a separate issue from the “draft revert” glitch that this patch appears to have successfully fixed.
The corruption issue has actually been in a game for a few years now.
Having all that said, I have no idea if BOTH things are now fixed. Perhaps they fixed the revert issue only. One could test in offline mode by simming out 5-10 years and see if the save files corrupt at some point. To be honest when I play offline CFM the furthest I have made it was 7 years and I even drafted for the the 8th year but never got around to it. It did not corrupt for me. I have played offline CFM’s 3-4 years out regularly and have not personally experienced the corruption issue.
Lastly, I read if you turn off coach firing for all teams it would fix the corrupting issue from happening, because no coaches would ever need to be signed. To me that is lame then because the coaches and playbooks across the league never change, and you would have all coaches in the league all be in their 70’s, 80’s, and 90’s of age (which would be kind of funny).