That seems to be the only way Suguha's story can turn out that isn't just "and suddenly out of nowhere she was taken by another NTR man after trying to confess to Kirito and he told her no". Because really, at this point she has clearly lost it, she's deceiving him in VR and becoming beyond obsessive, she rapes him whenever she has a chance in real life and records it probably to masturbate to it later at home when she can't be with him, and she's clearly starting to grow aggressive/resentful whenever Asuna or the other girls are mentioned.
The only 'realistic' way Kirito turning her down should make her react at this point after she has gone this far would be to snap and blackmail him/force him or worse with how her character has developed XP That's why I said that the 'nicest' development would be for her to keep dragging things without confessing to Kirito at all or revealing who she is in VR, at least not until the game is over or as part of the epilogue, as that's the only way it can fit within the 2 established endings at all.