Huh, so it was. I always remembered it as Humanoids and Monsterous Humanoids.

And yes, that, I think, would be a nifty little change. Makes it a bit more open access and offers some other encounter options for DM's who want to use it while creating a bigger pool of options to go with it for PC's.

And with regards to Succubus being a template, that could actually be a cool change. Who doesn't like being able to add Cha boosts and ability's too a race described as being beautiful or Charismatic anyway? Gives you something to Enhance flavor.