No idea. But that can't be good. The long delay in the press release suggests that there was some issue that was not immediately resolved. Had he told them he was not coming during the signing period, they could have gone ahead with the release you are seeing now.
What is confusing is that a picture of his signing ceremony at the Patrick School was posted on twitter on November 21st. Either he never sent in the signed LOI or there was some other issue, perhaps with his admission. Just speculating. I suppose there is a chance that he will still end up a Bison but I am not optimistic.