It was unfortunately that Leverkusen did not win Europa finals but that did not stop them from having a remarkable season. They were much successful last season than any other season because they won Bundesliga unbeaten. No one expected Atalanta to be the winner of last season Europa because they were underestimated.
I believe that next season Atalanta will try their best in Champions league and same with Leverkusen but I don't know if they can go far, because champions league is not the same with Europa, and in the previous seasons, Europa champions don't go far in UCL.
We know that the level of competition in the Champions League is not easy even though Atalanta and Leverkusen hold the status of European League finalists. However, both teams have good self confidence, because they had achievements last season. This is different from other Champions League contestants, who managed to get tickets but did not win any domestic trophies. I think the strength of Atalanta and Leverkusen should be taken into account in the Champions League next season, they could be a surprise team, especially as their manager is still at the club. The squad depth of the two teams has not changed much, I think there has actually been an increase, this will be a good sign for them.
The most realistic target that Atalanta or Leverkusen can set is to reach the quarter-finals or semifinals, because I doubt they or any of them can reach the final. The Champions League will actually never be easy for anyone, mentality and experience determine everything there. Apart from all that, the presence of these two teams in the Champions League is an attraction in itself, considering that they had an impressive season last season. Everyone is curious about their performance next season, especially when they play in the Champions League.