To retort, I am not claiming anything in affirmation. To start, I wholeheartedly agree with you that none of this buttresses Touka's impending demise, so if that is all you were you were trying to say, we are on the same page. And I say this is as someone who wants Touka dead.
All the same, I feel the key theme you are overlooking is context. Supposed homages to past artwork do not inherently disprove or corroborate anything. To ensample, the image with the ray of light piercing down on Kaneki as he looks up - while it is visually similar to the final spread in chapter 75, that's the extent of it. It has nothing to do with the context of the original which featured a certain poem. It was posted just before his memories returned. To further add to this point, Ishida illustrated Kaneki in the photo with complete white hair (its current state) when the chapter before he was "Haise" and the very next one was "Black Reaper." The poem complementing it referenced events that still have yet to occur in story. For example, you have some Etofags like >>159476912
saying that she may corrupt Kaneki. That actually is not entirely impossible given their "mother"/"son" dynamic paralleling with the Black Goat's Egg. The poem actually does hint at Kaneki killing (and regretting it, just like The Black Goat's Egg MC), as well as a rather abusive dynamic with Eto. >The bloodstains won’t come out, no matter how many times I pour warm water on them, they won’t come out.>Only words begin to dissolve everything, and get stuck in the drain.>And you become unable to forgive yourself, unforgiving.
- and the rest is Kaneki being tormented by "god" (Eto), or rather a failure of one that "truly loves [him], only she doesn't know how to love."
Will it happen? Who knows. But Ishida drawing all these images of Eto's hands wrapping around Kaneki does not inspire confidence.
That said, none of that proves Touka's death. But the "corrupted" Kaneki aspect still has potential