For example, Ritsu Kire. If you look at his voicebank, you'll notice a few folders in the file, labelled with pitches. If you listen to them you'll find that everything in a folder was recorded at the same certain pitch. Then Ritsu Kire's OTO.ini has samples such as "a kaC5" in which C5 is the suffix. In the Prefix.map, you'll see that pitches from around C5 and up will have "C5" in the suffix.
So, aliasing is actually very important. (on a somewhat unrelated note, CVVC banks with vowel-H combos can be double-aliased as ending breaths)