In 2019, Apple announced their intention to deprecate kernel extensions (KEXTS) and replace them with system extensions. System extensions were released in macOS Catalina 10.15. Beginning in macOS 10.15.4, the use of kernel extensions will trigger a notification that the software using this type of extension includes a deprecated API and an alternative should be provided by the developer. An official date has not been provided for when Apple will cease to support kernel extensions.
How is this going to affect me?
Programs that rely on kernel extensions may cease to function properly including, but not limited to, virtual machines, antivirus, and other security solutions. If you are running macOS 10.15.4, you may see this popup:
If your company uses Cylance through Rippling, Cylance is currently working on an alternative to depending on kernel extensions. In the meantime, Cylance will continue to function normally and no immediate action is required.
You can read more about legacy system extensions on Apple’s website.