By looking at the latest update of Nezumicon I'm starting to feel that maybe Artificial is losing interest in GG.
1) He works on it for a few years now.
2) GG is much more complicated in terms of production since its not a simple slice of life (while Nezumicon is). It requires playing around the action, thinking through battle scenes and other complex tasks. Nezumicon is more prosaic. Making gags and jokes is eaiser than serious and dramatic scenes.
3) GG's universe is much bigger, which complicates the writing of new chapters, since you have to keep in mind everything you already wrote.
4) The amount of typos and other errors is very low in Nezumicon unlike GG. Also the text construction is more sophisticated and accurate there. Characters sound more natural and lively.
I may be wrong, but it seems to me that Artifical, like many other developers, was making GG as his first big project. He learned a lot during it's production, but as it would be so long to recreate the entire game with this gained knowledge, that starting the new one from scratch is a better idea. After all, in terms of motivation it's often more tempting to write a new story rather than rewriting an old one.
It doesn't mean that GG is doomed of course, but for me it is a solid answer why we shouldn't wait much from new updates. Keeping hopes for an ocean arc though.