Are these generic sims based on someone or on some past characters?

I think they all appear in CAS when you make a new sim. Also, they're on the Gallery under the official Maxis account (at least I think it's the official one). They all have backstories a such. I don't think I've come across the one in the red shorts. They do have one on their Gallery page that has those clothes but he looks completely different. His name is Jayden Armstrong.