Quick question. If i started a new map, will humoids "arrive" or start to grow without placing them myself? Hard to describe, but... if i did absolutely nothing, and came back 10k game hours later, would there be humans, dwarfs elves or any of that, or still just lowly creatures because I never manually placed a humanoid in the first place?

Maybe one of the age events might spawn in something, however the likely answer is no