lots of doujin stuff wind up on pixiv. there's some merchandise on their platform around the event, but I wouldn't dare import any of it
wanna squeeze one out to this doujin
Well I can't guarantee there's nothing more to it, but given Fate is by far the most popular series for doujinshi these days, it's hardly a surprising choice.
Imagine if Type Moon did see something new, unrelated to Fate, Melty Blood or Tsukihime. But I think between Tsukihime remake and Extra they've already capped out on "big announcements" for a few years.