The Cleveland Indians ended the 2019 season in a National League park. Had they not taken a swan dive out of the playoff race in the two games prior to their final series in Washington, the Indians would have been fighting tooth and nail for a Wild Card berth without their designated hitter.
On paper, an American League team playing its final games in a National League city benefits not only the NL team, but also any AL team who is not playing Interleague games to finish off its season.
This didn’t turn out to matter in the grand scheme of things, and for the record, I would believe all of what I’m about to say whether it ever affects the Indians in the future or not.