I could not even find the source code for it on the official KDE
download page for it and from what I found it has never been
finished nor implemented well.
for compatibilty reasons automoc4 support is not removed but it
shall be in the future. automoc4 has not been maintained for a
while (last commit is from 2011) and the stable release is from
2009.
CMake version >= 2.8.6 provides the functionality for mocking so
I see no reason to not make use of it.