What is Apple doing with UUCP?
Those entries are examples that can be used as templates in user defined configurations. 

See the same examples at:

http://www.opensource.apple.com/source/uucp/uucp-11/configs/sys


You can see those examples in the same way as the phone prefix +555 in the movies. It there to show somebody using a phone, but the fake number/name cant be called. Placing an example with a ficticious hostname allows to have a template.