a lot of teams are popping off out of nowhere, this is making things way harder for Inter and Juventus to finish the season in a good position, Napoli, Atlanta, Lazio, Udinese, Ac Milan and Roma, all of them are ahead of Juve and Inter, so i can say that one of them at least is not going to even get a sixth spot.
You instead ask a lot of teams popping up out of nowhere 
. Even though what you mentioned are the old teams who have always been in Serie A even though in the previous season they were not in a better position than this season. Please note that every team always improves in every season so don't be surprised if there is a team that used to look weak, but has been so consistent this season. Like the team you mentioned.But in this case it proves that even though Serie A has many stars at big and well-known clubs such as Juventus, Milan, Inter, etc., the fact is that a club that has quality that can be called Standard can also be competitive at the top like Atalanta which has equal quality in players as well. Udinese.