They tried to schedule her for four separate episodes that season. They flat out admited that TGIQ became very meta about the chase to arrange a schedule for SMG to show up. And if she didn't want to, fine. I just got kinda irked when she then started making noises because of Ep 22 where Fox shut down negotiations with her because of salary and airtime demands. By that point I was entirely against her showing up. The final episodes deserved to be about the characters on the show. It would have been nice for her to have been around earlier in the season when it would have provided publicity that may have helped the show, but by the time the finale was being filmed it was a done deal and I wasn't particularly interested in it becoming about Buffy.