Unlike many other large subreddits r/books has not made any statements about the API changes. I did try and post something about it but it ended up getting deleted. At 22.1 million users this would be a pretty significant addition to the protest.
Does anyone know why there hasn’t been anything official?
At the end of the day, the only ones who can choose to make the subreddit private are the mods, and I don’t think they’ve given any public statements on it either way. It may simply be that the mods aren’t unified on whether or not to join.