Personally Myst, I don't think it's a big deal to use "it" in Vocaloid/Utau context because outside of the avatar and namesake... take all of that away and it's only a voice. These synthesized voices can be interpreted and genderbent to fit whatever you want it to be (hence VY1V3/VY2V3 having no official human mascots and having the ability to g-flag and adjust the gender parameter in Vocaloid). It's not the same as referring to a living, breathing person as an "it" to dehumanize them.
While it's true that the voicebanks are just voicebanks, there's the fact that Ritsu (and other UTAUs/Vocaloids) has a CHARACTER attached to the voicebank, with a humanlike design and physical/personality attributes and all. Ritsu is a lot more of a fictional character than the VYs (who were specifically intended to have no gender, design or personality) and how you treat fictional characters can reflect how you view/treat/respect real-life people.
Besides, this discussion was specifically about the character profile. If you're referring to Ritsu's VOICEBANK as "it" then I can totally understand that, but this was intended to be in context of Ritsu's CHARACTER PROFILE (i.e. the okama thing) so trying to justify calling Ritsu-character an "it" because of Ritsu-voicebank is pretty damn shifty if you don't do that for other UTAUs or Vocaloids.