Just as an anecdote- I had this happen to me. I was accepted into a program without any mention of funding. I was surprised, so I quickly got in touch with my POI in the program. He told me that decisions regarding funding were made later and they would get back to me in several weeks. Sure enough, they eventually did and it worked out fine for me. Like I said, I was surprised, but I guess that some departments just do it that way.