My issue is with those emojis is that they don't meet a few of their own criteria for a new emoji to be accepted.

Their guideline: https://unicode.org/emoji/proposals.html#selection_factors_i...

For instance, they suggest using "elephant" to evaluate the usage:

https://trends.google.com/trends/explore?date=all_2008&gprop...

The submission guidelines have changed over time. I would assume that, at the time, the proposals _did_ meet the guidelines.

The proposal has a section comparing the frequencies for "pregnant-man" and "pregnant-person" with "elephant". It was a criteria back then.

https://www.unicode.org/L2/L2020/20190r-swollen-belly-emoji....

Most (if not all) gender neutral emojis were proposed by the same person.

Uneducated guess--somewhere someone will have archived the discussion--but I wonder if the technical complexity was also a factor. If you've made the combining characters for gender, and you've designated which characters can combine with them, but you didn't plan for characters that must be combined only in certain ways, then you're looking at having to specify all that out, and then implementers will have do their thing, and it just... wasn't worth it.

Uneducated guess, though.

EDIT: Googled. Here is a person who knows what was up: https://jenniferdaniel.substack.com/p/did-someone-say-new-em...

The party in power wins by default on the little stuff. The opposition must "save their debate for more important things."

I don't know who is opposed other than those that want to pretend that pregnant transmen don't exist.

But that's not the system. They should be sticking to consistently using the ZWJ + gender to modify a base emoji and they aren't. Consuming three codepoints when one will do is silly.