yeah normally but i heard people are making this work anyways. likely steam knows the mess but dont wanna make it to public how you can refund, or a mass of people will all do it (that will happen anyway)
thats why you do it sooner then later before steam cuts you off.
give a sob story about how you were waiting for launch with your friend at a lan party all excited, to find out you have a single player game that you burned through the content in about an hour.