True, I just did that myself and the pages are not found. I can confirm that I followed the same link a few days ago and it was there. Now it's not.
The owner PMed me (im friends with them) and said this
My time working on TerraCraft has been a rewarding experience, and I am grateful for the opportunity to have been made a project with such a passionate and dedicated community. However, due to personal reasons, I believe it is in the best interest of both myself and the project that I step down from my role and therefore close the project.
Well, with all due respect to the hard work they put into the project it's kinda lame to shut it down like this.
Even if they are not going to work on it ever again, leaving it accessible in its latest state, especially for the people who bought it, or even giving it up to the community for pickup would've been a much better and much more trusted choice.
Well, who am I to judge though, it's up to them. I'll just be sure to never get involved with anything they do in the future.
skyblueyoshi said this (he forgot his password and mostly forgot about this project):
Due to personal reasons, I closed this project. These personal reasons greatly affected me, and I am very sorry for the inconvenience that I caused to this community. TerraCraft has been a very rewarding experience, and I am proud of the community that I built. But, this comment was basically a direct attack towards me and this great community, and you should keep your extreme opinions to yourself.