Atalanta did become champions in the Europa League they will not necessarily be the same in this tight Champion League because this match is also the mentality of a player or a team also affects it a lot of the class of English teams that are greater than Atalanta they fall more early because of intense competition.
I'm not underestimating Atalanta, it's just that when talking about the Champion League it will be difficult to say progress without seeing the match, so next season must see how Atalanta does it, otherwise they can fall early.
Their strength is still not enough when playing in the Champions League and they have to find some players if they want to look strong when competing in the Champions League. Several teams that have much better quality players than Atalanta are also not necessarily able to match other strong teams. Especially Atalanta who overall do not have much more experienced players to face the competition there.
The Champions League is different because it requires experience and mentality so that the strength of the team is also influenced by how experienced the players are. Although sometimes there are several teams that can play until the quarterfinals by relying on makeshift players, but talking about the chances it is very small for them to be able to keep up.