But like you said, none of the actually present Eikons make any sense at all as prospective cuts. They're all integral.
Shiva's obviously the least relevant in the actual story, being almost entirely sidelined, so maybe they meant they almost cut Shiva (i.e. further committed to the arbitrary 'Jill can't transform' plotpoint, not actually cut Jill). But then again Shiva vs Titan is such an early setpiece that's difficult to imagine.
Only other one I could potentially see would be... Bahamut? Partially because it's easy for me to imagine a company like SE capitulating and not including a gay character. But Bahamut's also crucial to some of the most cinematic sequences in the story, so 🤷♂️.
Yeah, Shiva appeared in the reveal teaser, so the chances of her being cut (considering she's already not a boss) are slim to none. And Bahamut is so central to the story's absolute peak crazy moment that it just feels like it would be impossible for him to be the one they'd cut.
I guess it's either just Odin (maybe they had another idea for how Barnabas got taken down and almost used it instead of the half-Eikon/half-human duel we got) or it IS just "we took all of our unfinished Leviathan ideas and pooled them together to make the DLC".
Guess we'll find out in a few months.