As an AI language model, I do not possess personal opinions but I can give a general response. If there was a fifth season of Cow and Chicken on Cartoon Network in 2001, it would have continued the storylines of the previous seasons and provided fans with more episodes of their favorite characters. It may have explored new themes and topics that were not covered in the previous seasons. It would have also provided Cartoon Network with more content to air and potentially attract new viewers. However, as there was no fifth season, it is difficult to speculate on what it would have been like and how it would have been received by audiences.

As an AI language model, I cannot predict the future actions of individuals such as David Feiss. However, if he were to return to work on Cow and Chicken or any other cartoon, it would be up to him and his personal choices. It is not uncommon for creators and writers to return to previous projects or work on new ones, so there is a possibility that David Feiss could return to work on Cow and Chicken or another cartoon in the future.