Ahh too late - the message is gone, I don't know how to get it back? I did check Security & Privacy, I saw nothing from Oracle there - it must be part of some other app?See the little house with the combination lock. That's the icon for System Preferences > Security & Privacy. Your legacy extensions might be identified there. Since they were running in Catalina, they'll run in Monterey. But they will cease to work someday.
Thanks, but it’s empty….Check the System Information app. There is an item for Legacy Software in the left column.
I actually checked there too when I saw it, and that section is empty too!Then go back to System Information. Take a look at the Extensions item. Your culprits will not be from Apple. I doubt you have more than a handful of them. I have just five non-apple extensions, but they are all shipped by Apple with the OS, and they have the same last modified date as the OS. Knowing that, you should be able to figure out which one(s) is/are legacy.