It’s a more conservative description, and it’s likelier. Maybe someone would be religious about manners in general, but I think pronounced devotion to a single table manner is odd. Again, it’s possible. There are very uptight people in this world.
I’d rather slurp especially when eating noodles and the like, most especially for Japanese noodles: Udon, Soba, and Ramen. My family always scold me for slurping even when eating spaghetti or something. lol