Was just thinking about everything and remembered something. Under the cut for length and Shadowbringers/Endwalker spoilers!
Considering Mitron being reincarnated into a male body whereas Mitron's ancient self used female pronouns (see figures below) it brings up lots of fascinating questions on the Ancients, gender identity and the Sundered world. Also, considering the fact that Mitron and Gaia's arc specifically states Mitron was able to find Gaia whatever her current form, it suggests a trascendence of gender. Mitron is a Sundered shard, however recognised (her?) existence as Artemis and bond with Gaia.
All of this suggests gender is not necessarily fixed in the case of the Ancients, or their reincarnations. Considering they are able to change their appearance and often do so, it reinforces the notion that the Ancient concept of gender is much more fluid than we would assume.
Edit, this is important: This is relevant as Gaia/Loghrif reacts and responds to Mitron-as-Artemis rather than Mitron's current form, suggesting differences in how gender is perceived by other Ancients as well, adding to the idea that gender is seen as more fluid and transcendent.
So, in terms of Emet-Selch, it could easily be interpreted as having utilised this (see below for in-game lore). It is made explicitly clear to us that he has lived 'a thousand thousand' lives, each with unique experiences, as highlighted in his famous monologue. Therefore it's absolutely not a stretch to say he's inhabited a female body, I'd say based on canon evidence it's more likely than not.
Furthermore, it's basically stated that Emet-Selch's personality is characterised somewhat by theatrical acts, as well as his love for theatre itself (see below) as well as acting being a common theme in this story. This links back to the concept of performing roles such as 'hero' or 'villain'. So therefore it's not a stretch to say Emet-Selch could be considered a drag artist, or at least admire drag as an artform, that takes archetypes and embodying and/or exaggerates them. It makes thematic sense with his story arc and interactions with other characters!
That's not to say there's no room for headcanon or other interpretation. The fact that it is so fluid can itself lend itself nicely to other interpretations of Ancient gender identity, expression and performance, including more rigid ones, where gender is the same regardless of these factors.
So, in conclusion, there is plenty of textual evidence to suggest that the Ancient concept of gender is wildly different from the Sundered world, so therefore Ancients existing in Sundered worlds approach gender identity with a performative approach (specifically highlighted by Mitron and Emet-Selch) which can also fit in nicely to many headcanons and interpretations of their own approach to gender.
Therefore, in the spirit of Pride Month, go forth and gender!
