Momo
Octorok
I think Mitsuda confirmed on his blog that the tracks in the reveal trailer were composed by him. So there might be some Anuna in there.
The last part was:
And DeepL translates it to:
Since the game he was talking about since last year was most likely this one it sounds like this was an even bigger project.
Instead of Mitsuda/Procyon Studio, I think ACE are handling the production/business side of the soundtrack. They recently formed Sekai Walker Producers and were credited for music management & coordination in Xenoblade DE. Many of CHiCO’s posts on social media indicate that they are probably managing the OST for XC3.