>>15432713>>154329531) That video where she said she rejected a friend was (at least according to her, verbatim) in school. Maybe she was referring to Suisei and threw in that school bit to muddy the waters and prevent too much speculation. Maybe not.
2) Suisei and Kanata are still on amicable terms and we don't really know exactly how close they are between the scenes. They're friendly at the very least.
I'm not saying that they're together or anything, but I'm saying that this headcanon (while founded on a grain of truth) is largely exaggerated 80% of the time