I think you are close.To dovetail into the questions of "are all Goblins Fey, are all Gith Aberrations"...this pretty clearly signals thst WotC doesn't mind having inconsistent Creature Type within a Species.
I also really, really think WotC is cooking up an Inber Planes Setting product.
It could be an elemental themed First World product.
(I hope not, I already have that mythos worked out for my camapign. But maybe there will be stuff to steal).