Exactly... but they already do in some cases, where the antenna was designed by the architect as a supposedly integral part of the design. One example is Commerzbank
in Frankfurt, along with several Australian skyscrapers.
The antenna on One WTC will in fact not be a TV mast at all, it will be decorative - with all the broadcasting equipment arranged in a ring around its base. It might be odd to call a utility pole decorative though, when there's so little effort put into making it aesthetic, and when even the architect (David Childs of SOM) disavows it in the planned form.