Translating the narrative into mechanics looks more like the following.
Elves are essentially outcast celestials.
• Elves are originally clones of the mutable Corellon, a celestial.
• These mutable elves preferred to keep humanoid forms.
• Shying away from mutability insulted Corellon.
• Corellon forced them out of the celestial − and dispelled their mutably.
• Locked into humanoid forms, the elves took refuge in the fey wild.
• These humanoid forms are diverse. For example, sea elves exist in the feywild.
At this point in the narrative, all elves are ‘fey humanoids with celestial ancestry’.
• Some elves remain in the fey wild evolving there into eladrin elves.
• Some elves leave the spirit world of the fey wild, materializing into the material.
• Shadar-kai elves immigrated to the spirit world of the shadow fell, thus are shadow humanoids.
At this point, those elves that are material humanoids have both celestial ancestry and fey ancestry.
The eladrin and the shadar-kai are incorporeal spirits.
(The fey wild and the shadow fell are both spirit realms. They seem to be ‘deep’ in the ethereal plane.)
Suppose Corellon voided any connection of his clones to the celestial, in which case, these former clones are now elves in the fey wild, who are strictly fey. If there is no trace of their celestial origin, then the eladrin are fey only. Other elves are material with fey ancestry and so on.
Elves who return to the celestial as tulani, ghaele, fierre, etcetera are celestial (again) but now with fey ancestry.
But note Corellon, an ‘absentee parent’ to his clones. More than that, by driving his clones out, Corellon turns out to be a highly abusive parent. His alignment as ‘good’ seems doubtful.
Elves who are healthy survivors of the trauma, would have nothing more to do with Corellon.
Elves who return to the celestial to stay with Corellon are dysfunctional, and the situation there is disturbing.
Corellon seems non-good and unlikable.
Honestly the 5e spin on Corellon is very different from previous editions, there was no evidence of this absent parent crap so either he grow out of it, or they messed him up to make Lloth look better which I don't like.