Earlier Apple shared a new support document in which it says that the legacy systems extensions will not work for a future version of the macOS as these extensions are not secure and reliable as modern alternatives.
Last year Apple informed the developers that the macOS Catalina will be the last OS that supports legacy system extensions and that Apple will be working on new transitions to further modernize macOS. The new updates will bring several upgrades to the macOS and make it better and work faster.
Apple in its support document tells its users, “Until the transition is complete, your Mac displays a message when a legacy system extension first loads, and again periodically while the extension remains in use. This gives you advance notice that existing software on your system loaded a system extension that will be incompatible with a future version of macOS”
Currently, Apple has not given any final transition date. Apps with kernel extensions will continue to work in macOS Catalina.
The support document also tells that by working beyond the extensions the developers will modernize the macOS. It will significantly improve the security and reliability of macOS. It will also enable more user-friendly software distribution methods.