I'm not sure how much Mason would've actively interacted with the others, since they either seem uncomfortable or tend to avoid him, but I could see Morgan reminding him of a certain person. That could either be a good thing or a bad thing though, and I don't know how that would effect previous interactions.

Also with the whole altar knife thing, if Morgan ever brought that to school I'm sure Mason would've questioned her about it, and mention that bringing knives to school is a no no.