To be fair, two of the four discussed here (U+1F6AB and U+1F6C7) are early "astral plane" emoji just after Unicode gave up on Han unification as a plan and moved back to trying to better round-trip existing encodings. The existence of emoji in general is partly Unicode's mea culpa for attempting Han unification in the first place.
(It was an odd sort of apology, given most of the damage was already done and the astral plane should have probably opened up a lot sooner in hindsight, but it was a fascinating sort of apology in the way that emoji has done more for Unicode acceptance testing in first-language-English developed applications than just about any other block in Unicode history.)
(It was an odd sort of apology, given most of the damage was already done and the astral plane should have probably opened up a lot sooner in hindsight, but it was a fascinating sort of apology in the way that emoji has done more for Unicode acceptance testing in first-language-English developed applications than just about any other block in Unicode history.)