Too bad there's still no information; i think NK must be hiding the info so there won't be any spoilers. either that or they're still working on the sprites and concepts.
If you want to see the updates being posted, Please follow the Bloons TD 6 Page
but literally nothing happened ever since the page's creation
Yeah, because NinjaKiwi still hasn't announced more information about the upcoming game, which is why this article still hasn't been updated.
Well, i think spoilers are just free sneak peaks that may get un-anticipated, so nk doesnt give spoilers.