Я тоже так считал. Почитал регламент на сайте УЕФА, оказалось, ничего подобного, жеребьевка всё определяет. Так что вполне может быть и русский финал.
Quarter-finals
6.11 The eight winners of the round of 16 contest the quarter-finals, for which the pairings are determined by means of a draw. The quarter-finals are played
according to the cup (knock-out) system, with each club playing each
opponent twice, in home and away matches (two legs). The team which
scores the greater aggregate of goals in the two matches qualifies for the
semi-finals. Otherwise, the stipulations of Article 7 apply.
Semi-finals
6.12 The four winners of the quarter-finals contest the semi-finals, for which the pairings are determined by means of a draw. The semi-finals are played
according to the cup (knock-out) system, with each club playing each
opponent twice, in home and away matches (two legs). The team which
scores the greater aggregate of goals in the two matches qualifies for the
final. Otherwise, the stipulations of Article 7 apply.