Kudos to Bluskale, who pointed out a new note on the now closed Mill main page, regarding the future of the Myth map and file resource site:

The Mill will once again be back in running, however we regret not by the previously faithful Frigidman. Also, the site will most likely not be under the same URL as before.

Inspection of the source reveals no this is only a cruel joke lines, so I imagine we can expect to see a successor to the Mill at some point in weeks and months ahead.