TFTNT!
There is speculation that Harth has already changed the timeline in the comics to why things are so messed up not just with Spuffy but other dislikes or things that don't fit maybe.
With his ownership of Slayer memories, Harth has come from the future to destroy Buffy and all the Slayers, stealing their power for his own. At his side are demons and evil-kind, a massive army that Buffy and the Scoobies weren’t expecting. To even the playing field, the gang travels to the future to recruit Fray and learn of their dismal fate—should they fail in this battle against Harth.