The last official contact regarding the server (Rey del Sexo, I believe) has been silent. I don't think his email has been bouncing, or one of the regulars would have said something. He did indicate during the last outage that dealing with the server involved physical travel.
I'm assuming that this is the death throes.
There is some kind of massive torrent out there representing ASSTR as of about 2017; Eli the Bearded retrieved it but wasn't certain of the prospects of making it sensible because of the javascript embedded in a lot of the files. Eli also hasn't indicated any interest in setting up a full-fledged website.
There's also asstr.xyz; I don't know who created that but it has a large amount of ASSTR material from the ftp folders view. It doesn't appear wholly complete, but one can't tell whether that's because files couldn't be pulled over or because some authors had removed their stories from ASSTR.
There's also an effort being discussed on a.s.s.d about a newly created website (ASSLR). I've put all of my stories there in a single HTML file but they're not ready to handle a lot of traffic yet. They're still working out thoughts about content policy, FTP access, possible story tagging and other matters.
I hope this is informative.