It doesn't even make fucking sense, Susie has no idea how useful Noelle would be in the dark world and the only route where Noelle is a genuine force to be reckoned with is the WR, which completely bypasses this entire chapter and the next one so the scene never happens anyway. "Oh we totally need more help now Kris it's super cereal" just comes off as a roundabout self-justification from Susie when in reality she just wants to drag her girlfriend along because she's thinking with her labia now.
Normal route Noelle has barely any experience in combat and would be a giant burden that would need to be constantly babysat by the rest of the team joining this late in the story, not to mention the fact that Noelle doesn't even know the Dark Worlds are a real place and not just a dream she had. Her entire theological perspective would be put to the test just from the simple fact that she'd learn that the Angel, Prophecy, and Apocalypse are all 100% real and now it's suddenly her responsibility to stop the roaring now because her gf said so.