Yes, and after they rejoined all life, they intend to sacrifice the non-Amaurotine life to Zodiark to bring back the rest of the Amaurotines. Hence my assertion that the Amaurotines see non-Amaurotine life as being inferior and lesser, since they believe it to be a fair trade to bring the other 3/4 of their population back.
I've said it before and I'll say it again, we have no idea what sort of life they intended to sacrifice.

According to Hythlodaeus, Azem preferred to work with the locals to solve whatever problems they face, rather than call on the Convocation for assistance.
That was literally Azem's job description. The Convocation preferred to adopt a non-interventional posture in regards to the affairs of other cultures, but Azem's seat was specifically made so that Amaurot had a representative to the wider world.

Emet-Selch even tries to poison the rhetorical well by pre-emptively saying Hydaelyn's own hypothetical account of her summoning will be different and thus false,
But he was completely correct? At the point Emet makes that claim Hydaelyn had already given her account of how she came into being, and it's false.

but Hythlodaeus's account is different, despite his being a creation of Emet-Selch.
Was it really? All Hythlodaeus gives is a reason why they would fear Zodiark and seek to bind him.

to find out what went wrong and caused the Flood of Light.
What went wrong? But the flood is precisely what they needed to have happen for the rejoining, the only difference is the last domino was intended to be Cylva.

then given what we're told (many times) about Emet-Selch's soul-sight, he should have recognized Mitron in there.
Given that Y'shtola can't recognize WoL's aether after only absorbing the light of two wardens, I'm a little doubtful Emet would have been able to recognize Mitron's inside the creature that caused the Flood itself. I know his is far more advanced, but so is the scale of light in Eden, which was a fully transformed Sin Eater.

To the eyes of those who live in Amaurot's society, they are seen as lesser beings.
I'm not really sure where this idea comes from? The only times I recall the Amaurotines discussing other cultures, it's in the vein of them being friends and equals who should have their own autonomy, and that if Amaurot should set out to help them it should be for the purposes of devising a means to forestall such disasters in the future that it might be shared with the rest of the world. It's kind of a leap in logic to hear "we should not intercede on others' behalf" and read that as "others are lesser beings".