but they are still there,
This would be expected for this deep running app (which I agree should surely not be there). Just to explain what you are seeing, the command
pm uninstall -k --user 0 com.android.hotwordenrollment.okgoogle
does only uninstall for --user 0 (that is you!).
It is still there and it is not a root uninstall. So the system can can on using it, (while you cannot!)