RE: https://mastodon.social/@mikaeru/115583941639906512
Generally, new CJK Ideographs proposed by members of the IRG (Ideographic Research Group) go through several rounds of exchanges/discussions until they get approved or possibly postponed or rejected.
For instance, here is the page dedicated to UK-20538 ⿰㐅也 (with images as "pieces of evidence"), which eventually made its way to Unicode 17.0, encoded as U+323BF :


