No, it doesn't mean that. In act, Freightliners are now pre-wired for the addition of a tow brake - see
This Ad.
I belive you will find one or more factory-installed "T's" at cab be used to attach air-powered equipment. That's different than adding your own T by "tapping" into the air lines.
There is also usually a manifold with multiple pre-installed air line ports somewher, but that may be installed by the coach builder rather than Freightliner. My American Tradition has one in the left front bay.
If in doubt about where/how to connect, call Freightliner and ask.