Tbh I mostly agree with this line of thinking. It seems like Anna's sight specifically correlates with souls (e.g. her seeing burn scars on Charlotte but not mentioning them on Laura or Saphira; while the fire impacted all three of them, it seemed to scar her the most, if we attribute it to souls we can also attribute it to Cain, seeing as eyes are the "window to the soul" and she sees his as all black. this might be a bit of a reach though lol) so her not seeing Lin implies that whatever happens, that Lin might not have a soul
And if I remember right, Shade's prophecy didn't say the people would die, just that they would be "taken". And with the soul thing in mind, pluuuus the fact that Shade basically took Corey after he died, leads to the fact that Lin can't be taken because there's nothing to take lol. but the Lin in the scene COULD be the real Lin, and it's just that her soul was never taken because it merged with Arceus or she sold/destroyed it or something haha
Also something doesn't really sit right with me >_< the prophecy thing's last line is "for, forsooth, from foreshadowed, only two will be taken". Corey's death wasn't foreshadowed; it already happened when we got to Shade's gym. That leaves three choices: Kiki, Amaria, and Lin. We already know Amaria isn't taken, so whatever happens with Lin, I have a feeling the explosion thingy marks her losing her soul for good. Or something. Not to mention the "will" in his prophecy...if it had been Kiki and Corey, what's with the future tense? It sorta implies that somebody's soul *hasn't* been taken yet, but will be.