No more evidences to prove the glyph shape？ It seems unifiable to 黝 (U+9EDD) according to the pronunciation.

The analysis in the evidence says that the shape is composed of "hắc (黑)" and "ảo (幻)". As shown below, 幻 read as nôm "ảo" has one meaning of dark, obscure, etc. This is the semantic in this character.




xxx Is a different word, "u" with a similar meaning of "dark"

I didn't finish the above, but meant to say that 黝 (U+9EDD) is basically a different word "u", used in the compound "u hắc", whereas VN-F0188 is "ảo", having a wider range of meanings: "not current; obscure, ephemeral, etc." They should be kept separate.

Removal of the stroke from 幼 is pretty common historically:



(Quoted from the MOE Dictionary entry for A01549)

Potentially this could be a UCV level 2 if there are a huge number of variants of 幼 from V source.