I understand it's very possible that Liverpool and Leverkusen may not get to meet in the finals but then I don't think the council in charge of Europa would want that to happen because they know how well the anticipation on Liverpool and Leverkusen meeting in the finals has been on most persons an how much view such finals nis definitely going to get and that alone will keep attention to the Europa till the end of the Europa, except either of these team naturally happens to exit before the finals I think it will be best to allow them meet in the finals and the best teams should win.
Honestly, I don't really understand why you doubt Liverpool and Leverkusen to be in the final round? You know most people really want to see these teams in the final round because they are the most consistent teams in UEL. The final will be interesting if both teams are equal and they are in the best performance during this season. I don't see other teams that have better performance, Italian teams are good but they played very unstable this season. AC Milan, AS Roma, and Atalanta aren't likely to be in the final.
TBH, I want to see these two popular teams to meet in the final round but I still want to see the drawing of the next match schedule and indeed Liverpool and Leverkusen get guaranteed to qualify for the semi finals but we don't know whether the two teams will not meet in the round semi finals or will only fight other teams.
like in UCL when most people want to see Man City and Madrid meet in the final round but apparently have to meet in the quarter finals and this could have happened to Leverkusen and Liverpool.
so there is no doubt if Liverpool and Leverkusen qualify for the final round but depending on the match schedule in the semi final round and hopefully these two teams will not meet in the semi finals.