The dev said that all male characters will have verse scenes but do have preferences and will sometimes lean more into particular positions. I don't think any preferences have been clearly stated yet but I do think Prof. Rojas leans verse-top.
Thank you for replying! As Jeffrey said, all the male characters are verse but some of them prefer a position more than the other! That basically means that Prof. Rojas for example will usually be on the top, but there will also be some scenes in which the player will get the option to top him instead. I hope it makes sense! Sorry for the late reply, I've somehow missed it.