Beginning in macOS 10.14.5, all new or updated kernel extensions and all software from developers new to distributing with Developer ID must be notarized in order to run. In a future version of macOS, notarization will be required by default for all software."
Why does this change happen in a minor release of macOS?
This seems a totally incoherent timing (evenmore if you consider that Secure Kernel Extension Loadind is still plagued with UX issues and bugs).
I assume that the problem of signed adware has gotten bad enough to do something about it sooner rather than later.
The kernel extensions are a different issue and, in my opinion at least, unrelated to security.