OTLand is a community for anything OpenTibia related, so TwifySoft is definitely relevant to OTLand and the board is not going to be removed. If you don't want to see new posts of the entire forum, browse the specific board you are interested in and you shouldn't see anything about TwifySoft there.
I'm not interested in League of Legends (if anything, this is a board that should be removed because it's not very relevant here, but because of the demand from the community, it exists), I'm not interested in threads in languages I don't speak, I'm not interested in any kind of threads about TFS 0.3 or 0.4, yet I have to accept such threads showing up in the new posts feed because they are new posts on OTLand. That's what the New posts widget is for.
If there was a lot of activity about Hexana on OTLand, it would receive its own board too (just like I created a board for Pokémon Online or whatever that server was called when that was a big thing on OTLand). Besides, the TwifySoft servers bring in a lot of new users to OTLand, and they are not restricted to only the TwifySoft part of the forum. Eventually they might get interested in developing their own server, and they can start contributing/posting in other parts of OTLand than TwifySoft (I think it's safe to say that the majority of the members of the OpenTibia community are former Tibia players).