macOS 10.15 continues to strengthen the security of the Mac dedicated system, notably with a change in size: DriverKit. This new mechanism allows system extensions provided by third-party apps to be installed in user space rather than at the kernel level. The ” kexts Will therefore disappear with Catalina’s successor, in favor of user extensions managed through DriverKit:
For years, kexts are used by apps, however, and this whole ecosystem did not disappear overnight with the release of macOS Catalina. In the latest version of the system, Apple takes an additional step by explicitly telling the user that its system uses “obsolete” extensions that will soon be deactivated. If you have kernel extensions installed, the newly released version 10.15.4 will display an alert.
The alert indicates the name of the developer who created the kernel extension and a button links to this support page. We learn that the alert will be displayed when the extension in question is loaded for the first time, and from time to time thereafter. Knowing that with Catalina’s successor, the extension will no longer be loaded at all and the associated app will probably no longer work, or at least not correctly.
DriverKit is the way of the future and developers have a much stronger incentive to use it with macOS 10.15.4. Still, this new solution does not meet all the needs that previously motivated the creation of a kernel extension. The most common cases are handled by the new mechanism, but there are still around 25% of cases that will no longer be supported with the next major system update.
Update the 03/25/2020 11:03 : If you are using a hackintosh, you need not fear this change. The new macOS policy only concerns extensions installed by apps, it does not affect extensions managed by Clover or OpenCore. I updated my hackintosh this morning without any problems and without doing anything in particular.