No. As in my previous games, you'll be able to choose in each nsfw scene if you prefer him to top or bottom. The scene in the demo was the exception.
EDIT: in the end, there will be top-only characters, bottom-only characters, and a switch.
I think I've shared it somewhere, but not sure if it was here or on Discord... Anyway:
-Gabriel: 95% top
-Ivaan: 100% top
- Jacob: 60% top
- Kevin: 100% bottom
Gabriel will have a total of two bottom scenes in the regular game, plus one more in the DLC. Jacob has one bottom scene in his route, and will have two more in the DLC.