Sounds like what you want is already offered and, in fact, has been done before in any of the three main sections. I'm not really looking foreword to adding a dead-on-arrival subsection to a forum that already has 3 sections that under-perform on a near permanent basis. I'm going to dismantle your arguments one by one;

[quote]So I asked about a World-Building section because for those of us who like building exactly that—worlds. It often requires time, patience, inspiration, and having a “canvas” ie. a blank thread or document where you can just design all of the pages, lore, maps, etc. that you would want to put in your game and basically, being able to design your game right there in the thread before you post it up. You could even design it with other players such as your co-GMs. Share the work.[/quote]

I am unsure what you are asking for. Are you asking for 'literal' world-building functions like a map designer in the forum? I venture a guess and say that you're not but the sentence 'being able to design your game right there in the thread' throws me off. Otherwise, I'm really unsure whether this even is an argument - a blank thread is a blank thread, whether it is in world-building forums or in test forums. You can already design it with other players namely through the 0th post (which is not an ideal function but whatever). Anything else can be substituted by careful planning and organization. 

A new sub-forum isn't going to help you with any of that.

[quote]I have mostly been using a Character Thread, which I would like to strictly use for my characters, but seeing how there isn’t a place for me to post up my world-building elements that has been the only place where I could post those ideas. So rather than clutter your character thread with world-building lore, maps, graphics, etc. Why not just have a World-Building section added to the Guild? They exist on other sites I role play on and they are constantly in use. People always have ideas and creative/artistic minds will always exist.[/quote]

You can make two character sheet threads or even make a bestiary in the guides section (which has been done before). [url=https://www.roleplayerguild.com/topics/167471-encyclopedia-ein-sof-a-guide-to-a-colloborative-persistent-world/ooc]Point[/url] in [url=https://www.roleplayerguild.com/topics/165133-a-guide-to-the-lore-of-the-abandoned-hope-universe/ooc]case[/url]. You don't need a new sub-forum. [url=https://www.roleplayerguild.com/topics/164519-the-world-of-areth-gladiators-of-arlen-lore/ooc]Just[/url] fall in [url=https://www.roleplayerguild.com/topics/165133-a-guide-to-the-lore-of-the-abandoned-hope-universe/ooc]line[/url] with [url=https://www.roleplayerguild.com/topics/125566-aveeno-lore-maps-info-canons-world-and-etc/ooc]the masses.[/url]

inb4 all of these can be placed in the new sub-forum!

Yes and your bestiary and whatever else can be placed in the guides thread.

As for the fact that it exists on these other forums - that's really cool. You know one forum I used to frequent had a payment system with made-up money that was arbitrarily handed out. Why not add that? Maybe it's because 'more more more' doesn't fit in my forum design philosophy but really, less is more. Not everything needs its own specific sub-forum. You can make due with what we have now, easily.

[quote]For one of the games I GM, I have a bestiary for all of the creatures that my players create. My players create very detailed descriptions for the different beasts found in the world. Rather than create a “Character Thread” for beasts, lore, maps, worlds, etc. This thread would go into the World-Building section and linked to my game for reference and I won’t have to worry about cluttering the Character Submission section with World-Building elements when it is specifically designed for character sheets. Instead, I can put the bestiary in the World-Building section because the bestiary is apart of my game’s lore.[/quote]

Put it in a guide. A character thread will be the same no matter whether it was made in this new 'world building' sub-forum or in a character storage thread. 

[hr]

It wouldn't inconvenience me in the way that that stupid 'Expanding Horizons' has inconvenienced me (under the impression that world building forum will be low, low, low in the list of RPG's frontpage) but I have to object to adding more dead-on-arrival forums. I predict if this were to be made it'd follow the same trend as EH - interest in the first week and then a very sudden death with only a trickle of activity after that.