Well, this seems like an 11th hour announcement, many of the applicants might not be watching HN at the moment and may not be able to exercise their right to "unapply" before the deadline.

But those are problems for the fainthearts who get deterred with this kinda announcement.

For the rest of the bravehearts its 'ok', they should feel like they are at day 1 on the market and its all bare now. Just that they should gear up for a much quicker launch in case of a possible rejection, which they anywayz should be - "hope for the best and be prepared for the rest/worst".

Let's face it, trustworthiness, bias, plagiarism and wisdom are all human traits.

@PG: Just a thought from a novice. This kinda late announcements/disclosure may taint YC's image like those "conditions apply" advertisements. An announcement early on would be better. I hope you are not doing this intentionally as a first filter for the applicants and hence reduce the load of applications automatically.