It seems to be asking about how to recover information from a hosting service that has fallen. It asks whether the lost content is recoverable. So here's my overall question? Should questions about recovering content from hosting services be on-topic here? Or should they go somewhere else?
I think this is going to be a bit of a thorny one.
In principle, I think yes they should be on-topic: hosting your code is an integral part of open-source so it feels right that we should have questions about it. However, questions that are more customer-support focused should be off-topic because we're not best placed to answer them.
The distinction is the difficult part. What, exactly, should make a question on-topic?
Perhaps we distinguish them simply by who - who's best placed to answer. If the question is obviously about an open-source focused aspect of the hosting platform (like how do I choose a hosting platform?), it's on-topic; if a company representative would be better it's not.
On Stack Overflow (and most other sites), we do allow question regarding the tools and platforms we use. I don't see why not here.
If you have a GitHub questions, which is a platform for open source projects, I don't see why we should not accept it.
Codehaus is gone. They don't need customer support, as they no longer have any customers.
The question also isn't from the standpoint of a former customer. It's from the standpoint of a user or potential user of that project, trying to track down old information about it.
So I don't think that question is in lieu of asking Codehaus for customer support.
It was also once a reasonable-size open source hosting platform, and instructions on how to find information about projects that used to live there will use useful for future visitors.
General "how do I use that site?" could go to Web Applications, but this one probably doesn't belong there, as its not about using the web app. So I think it best stays here.
(I'm not sure general ones about open-source hosting webapps should go to Web Applications; I suspect not. We're probably much more expert in them than the general audience on Web Applications.)
Well, a lot of people use/used Google Code and Codehaus. They are/were important to the open source community.
Further, we might get questions about SourceForge, BitBucket, GitHub, whatever-else very frequently, since many software developers use them.
If in the future, say GitHub, decides to change some of their policies, change the way that the Open Source community consumers use their services or change something else, I think that this community would be a very nice place to ask about that.
So, questions about open-source hosting services should be on-topic, since a lot of people uses that for developing Open Source Software.