The whole magazine/website to which this series moved to stopped continuing any series that were running in Girls x Garden/Comic ExE, which is a shame. They usually just publish a new oneshot every two months or so, and also publish anthologies like Avalon/~bitter~/Alter/~Karma~ or Qualia-Envy/Jealousy-.
Maybe it wasn't profitable to work on the series anymore (a tankobon of the series was never published even though plans were there, I saw some tweets about it but they got deleted again), maybe they stopped having resources or a readerbase (they moved from Comic ExE after all, which definitely had more readers, even though it makes no sense to publish SFW Yuri in a NSFW het porn book, but it was an experiment), maybe the editor got fired or stopped having a say, who knows.
The new gxg website is: http://www.comic-medu.com/wk/gg_shortstories and of the series is: http://www.comic-medu.com/wk/gg_futarigoto.
So while I'm quite sad, it most likely received the axe. Our group will of course work on any possible updates and I personally am keeping an eye on the artist.