Square Enix has said they'll make FFX-3 with enough fan demand. Hopefully the opposite is true as well, or they will change it and make the FFX-2.5 novella noncanon.

The Final Fantasy X-2.5 Novella ruins over a decade of memories and emotions that players of FFX and FFX-2 have. It taints and ruins Tidus and Yuna's love, makes the events of FFX-2 futile, and ruins one of the most beautiful stories in the history of videogames. Please do not continue this story. We don't want Yuna to see Tidus to kick a bomb, explode, and have his head fly over to her. We don't want any sex or summoning dead Tidus nonsense. We just want it to end at X-2. No audio drama, no novella, no FFX-3. Please :(