Tomorrow or one day after, as he wrote in the last post 16h ago.
But I wouldn't expect much, as the changelog for 0.39 is:
And for 0.40 it's pretty similar in amount of content:
According to his previous post, he didn't work on his game for past 1.5 months due to some family stuff problems. So I would probably rather wait more time for some meaningful amount of gameplay, of course if the dev still has a passion for the game.
I did not really understand what he meant in his previous post on patreon when he said that he was going to remove some routes from the game. There were closed post with a poll, so I can't tell what it is all about. I hope he wasn't going to delete the main routes like netorase or netorase 2? Because if so, that would literally end my interest in this game, since those are the only routes I'm interested in playing.