Okay, is your list of the Humaniods meant to be playable, like some 3.5e monsters in the MM? And by humaniods to mean the creature type or the basic body shape?
I see "Humanoid" as − by definition − able to be a player character. This creature type tends to exhibit a humanlike bipedal body shape, but not necessarily. More importantly, Humanoid means having consciousness, free will, the ability to learn, and form social groups and cultures. Regardless of body shape, it is humanlike in the sense that a reallife player can use the Humanoid player character as an avatar to play oneself.
At the same time as having player character stats, Humanoids also have entries in the Monster Manual, with monster statblocks, for combat encounters, often as members of an Evil aligned faction that is adversarial.
I think they should go ahead and include the Chwinga, instead of reprinting its stat block in every other adventure.
I love the Chwinga. Its concept is closest to certain kinds of animism.
In D&D, the Chwinga is an Elemental that is native to the Material Plane. However, rather than be an "Elemental" made out of some elemental state of matter, it is an Elemental "spirit". In other words, it is the outofbody projection from a some natural feature, such as from a Plant (understood as an Element), or from a shape of Earth or a puddle of Water. When the Chwinga dies its consciousness returns to the Elemental feature. The Chwinga projection adopts a specific Tiny form.
In other cases, the Elemental projection would take on other forms instead. For example, a Giant who is native to the Material Plane, is best understood as the Elemental spirit projecting outofbody from mountainous Earth, glacial Water, volcanic Fire, or stormy Air. Some of these outofbody projection manifest as Elemental matter, such as made out of Fire or Ice, but other projections manifest in forms of flesh and blood, such as Hill Giant and Goliath, and perhaps Orc.
All of these projections of the consciousness of natural features of nature, puts the finger on how many animistic traditions view the world, including Norse and Norsesque. The Norsesque Elf is the projection out of the Fire of natural sunlight, associating with Air of the upper atmosphere high above the clouds. The Celticesque Elf is the projection of the Earth of the liminal surface of the soil, and associating with the fertile areas of the Element of Plant.
The Chwinga has the method for how to do these kinds of concepts in the context of D&D mechanics and narratives.
The Chwinga deserves to be in the core rules of the Monster Manual.