From their FAQ page
Q: I just pledged. Why does the download portal still say that there are no downloads available?
A: If you've waited an hour, and the downloads still do not show up, please contact us for a download link by e-mail.
The download portal is dependent on the Patreon API to update the user pledges, and unfortunately, sometimes it takes Patreon longer than normal to update their API, which in return affects our download portal. This is mainly the case at the start of the month, when Patreon is especially under heavy load.
People even ask each other for the dowload link and requested help in the latest version page. Really shows that the dev is full of shit