seems like you're trying to justify the disrespect of netiquette with "it's one of the most predictable things". Just don't spoiler.
This game is a work-in-progress that's been going on for
years. You should be expecting spoilers in a thread for discussing the game on a forum that that regularly engages in sharing of pirated media, regardless of providing its users with the opportunity to support the developers of the various multi-media that are shared here.
Remember, netiquette is secondary to common sense, and the fact that you use the word (a rare thing in the past decade) shows that you should have sufficient common sense to expect to see spoilers. The only exception to that, is when there are multiple threads dedicated to a game, with at least one being for the sole purpose of spoiler-free discussion.