Yes, right. Even though in football anything can happen, looking at the performance of Liverpool and Leverkusen it seems very difficult for them not to beat Atalanta and West Ham. As you said, Atalanta and West Ham this season are less stable, this can be seen from their respective domestic leagues, apart from that in terms of quality and squad, these teams also lost to Liverpool and Leverkusen. I have no hesitation in betting on Liverpool and Leverkusen winning in the first leg.
Liverpool certainly don't want to miss the opportunity to win the Europa League trophy this season to give the most beautiful gift to Klopp, who will soon be leaving Liverpool. Likewise with Leverkusen, they are safe in the Bundesliga. They only need one more match to win the Bundesliga trophy. So of course all their strength and concentration is currently focused on the Europa League.
Each of the reasons you stated could be a true fact for both teams, because in general both of them will be equally focused on the Europa League trophy this season, although Leverkusen will not consider it a gift because their current coach will still will remain at Leverkusen next season. But for Liverpool, it could really be a very unique gift for their coach who will be leaving the team at the end of the season. So Liverpool will also put all their concentration into the European League even though they still have to fight in the Premier League because the competition for the title there is still fierce.