They are going out in stages based on # of mod actions or karma. I think the lowest Karma threshold in the final batch was 25k. Which seems like a lot, but isn’t really, at least for the users they alienated in the API debacle.
This is just for the sign-up for information, though. Once they get the whole list they will start going down the list of sign-ups from the top, and start asking for money. Because this isn’t a free share offering, it’s a chance to buy at the IPO price. So even out of the list of Redditors who signed up, a bunch will pass, because if they had a few extra $10k sitting around, they would put anywhere else except Reddit.
And I don’t think they have broken out how many shares are part of this program. (To be fair I haven’t looked that closely). I predict that no matter how many people sign up, they will reject 90% just for the optics. They are only doing this for the free publicity, and rhe fact that they think Redditors will have emotional attachment to the shares for being let into the “club”. So they will only give out enough for the press to write stories about it.