I haven't seen Superia in 36-rolls for some time in Canada, just 24-rolls. Not sure why. Last batch of Superia 800-24 wasn't very good either (mushy colors, lots of grain) though the 400-24 still seems alright.
Fuji is discontinuing a lot of stuff lately, especially in 35mm (Neopan 1600, Astia, Reala). I can't seem them getting rid of Superia though, probably just reducing inventory overhead by going down to just one roll length.