There is still some activity on the fandom wiki. So for any casual observer, it doesn't look abandoned.

NetHackWiki (somewhen around 2010 or 2012?) moved off fandom when it was still called wikia. It took several years to overtake the older wiki in search results even though the old one was completely abandoned and vandalized by humans and bots, and active engagement by users to change links to the new wiki ___location all over the internet.

Expect a marathon not a sprint.