you said you will finish it in Q3 of next year 

But there is no news of next update for 2 months

I'm not the dev so it's only my opinion but he said it was only an estimate. Plus he has taken more than 2 months before either because of writing the script for the next chapters or technical issues

Whydoineedausername is correct; that was an estimate. There is news on new updates regularly, but they're exclusive to paying users, or you can join our Discord server, for general updates. The communication system here is less than convenient. 

I want to ask, though, "in time for what?" exactly?  I mean, is there something that would happen if I didn't finish my free game by then? :D
Also, that is book 3's end, the main story. There will be book 4, book 4 will be chaos.

The new public chapter will be out in a few hours, EO is making the android builds and they take time.