What do you mean by “Mojave is getting iOS security model”. What I’ve seen announced is that, as of 10.14, the system will ask the user when an app first wants access to, e.g., microphone or camera. Do you mean something else?
macOS is getting a new security runtime, the scope of Gatekeeper will be expanded, entitlements will be required for all security critical OS areas, application signing and registration even for apps distributed outside the store.
For Mojave, it will still be opt-in, later versions depends on how it will received.
"Your Apps and the Future of macOS Security"