This is flimsy, but it is at least in the vein of what should be sought after, and certainly outclasses all evidence from before. Still, it is a brief line, and doesn't really interface with any of the other evidence, so it would be very difficult to convince me of Low 1-C from this alone.
This wouldnt be useable with the line above about Zoe having experienced 'realities beyond human comprehension'? The character who said this line is the same one who experienced that.
Either way, this one is mired in issues. This is evidently from an individual who doesn't understand what they're talking about, and they provide two statements that are somewhat contradictory- the "void" left behind is attributed both to an intersecting reality, and an additional spatial dimension. What I gather from this, then, is that Dan Abnett does not know what a dimension is (which lines up with his writing elsewhere, iirc).
Should note, Kayn does seemingly know what he is talking about at least in regards to spatial dimensions, as earlier in the story its stated that the occular interface he is using to scan the anomaly works in three dimensions:
"Alone again, Kayn woke the astral portolan unit built into the corner of his quarters. The console rose from the deck, opening its steel petals to project a tri-dimensional local system chart into the air. He reached out and rotated the image, moving through stars, selecting and enlarging. A swipe of his fingers brought Ionan into view. His golden ocular interface engaged with the projection, and augmented it to a real-time display of exquisite detail."
You can just crtl+f 'interface' in that story with a bunch of instances of the interface he is using beaming information directly into his head.
Better than the other 2-A statement, but not really good, since it's again a person being shown possibilities, rather than an explicit statement of cosmology. It's made slightly more dubious by the earlier content of this CRT mentioning that things like fate and possibility aren't concrete timelines or set-in-stone things in this verse, but rather cosmic suggestions.
Funnily enough, they are concrete timelines:
the Chronokeeper
universe.leagueoflegends.com
"Once a member of Icathia’s governing council, Zilean is a prodigious elemental mage who seeks mastery over time itself. After using his powers in an attempt to save his people from the Void, he now drifts through the past, present, and future, bending and warping the flow of time around him. Zilean has traveled from Runeterra’s mysterious creation, all the way to its seemingly inevitable ending, searching tirelessly for any strand of fate that might undo his homeland’s destruction."
Icathia, most desolate and cursed of lands, was not always so. Theirs was a rich and diverse civilization, ruled by benevolent Axamuk, last of the Mage Kings of old. As the Shuriman empire expanded across the continent, Axamuk’s calls for peaceful coexistence were ignored, and his armies...
universe.leagueoflegends.com
"Zilean had spent decades trying to comprehend the mysteries of time and causality, and it seemed only he could move freely back and forth within the anomaly he had somehow created. These people had been saved, true enough. He just didn't know how to undo what he had done to achieve it. Through deep meditations and esoteric devices of his own design, he began to divine the strands of past and present that led to this moment, gradually learning how to move back and forth along them, looking for a future where his efforts had already succeeded...
It was there that he found the true threat: the end of everything. The great unmaking that awaits Runeterra.
Effectively, Zilean now exists everywhere, and always has. Even so, he is only too aware of the consequences of trying to bring about change in the world and sparking other unexpected destinies—often conflicting, and almost always more dangerous. Perhaps if he can find a way to save his own people, then the greater disaster might also be averted. "
Pretty much the entirety of Zilean's lore is him experiencing the infinite branching timelines in the multiverse to try to save his home.
Ekko (a character who creates and destroys timelines as a form of time travel) also has an interaction with Kindred (the verse's version of Death) that acknowledges him creating and destroying countless timelines with his Z-Drive