It’s working just as you’ve set your renaming pattern:
%ismovie%<MCEB-Movies\%showname% (%premiereyear%),MCEB-TV\%showname%\Season %season%##\%showname% - S%season%##E%episode%## - %episodename%>
E.g. The Cops conversion:
→ is not a movie, so it uses MCEB-TV\%showname%\Season %season%##\%showname% - S%season%##E%episode%## - %episodename%
There’s no premiere year in the renaming pattern so it doesn’t include it in your renamed file.
Also note that %premiereyear% only applies to Series, for Movies it would be %airyear%
I think what you want is:
%ismovie%<MCEB-Movies\%showname% (%airyear%),MCEB-TV\%showname%\Season %season%##\%showname% (%premiereyear%) - S%season%##E%episode%## - %episodename%>