For new Waifu Academy players there are search functions if they want to get help with something. And we all know that new players generally don't even use that, and even if there was an answer to their question on the last page, they will not see it.
If they want to discuss their experiences, they can still do it, there being less pages doesn't make a difference, it's not likely new players will start going through pages anyway. There's no way that'll ever happen.
If there are people who attack new players and mock their positive experiences with this game, I can understand removing those posts (Though joking about the newbie being there for a rude awakening should be ok, as long as insults don't fly at the newbie). The newbie also isn't a child, and having someone mention that "Great you could join us, I hope you will be OK with there's no more new content coming up, the only updates we get from this dev are new release dates" might save that newbie a pretty penny.
And lets not forget that this game will likely not have a new update releasing any time soon (Or I guess if it will release, it will have content that some other dev could put together in a month), the only entertainment that Waifu Academy is able to consistently provide is this thread. I have seen so many interesting posts on this thread, and losing them to the "removal wave" is a loss for the entirety of humanity.. Or at least the "Waifu Academy Community".
Can't wait for the update though, I will likely play the shit out of it once it releases! It will be a glorious 20 minutes to look forward to!