It's perfectly fine for them to ask for information before showing you the download links. From the information on the website they seem to want to create a com

It's perfectly fine for them to ask for information before showing you the download links. From the information on the website they seem to want to create a community in their Association, where members will contribute. They say that "All published plans are licensed under Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0).", so anyone who gets the plans can definitely redistribute them (put them in a GitHub repo or something).