Something I didn't expect actually happened to Leverkusen. Indeed, we don't know how good Leverkusen will be for next season after Xabi left the team. But I really don't expect Ten Hag to replace him.
Some players left, maybe Ten Hag will also bring some players he likes to Leverkusen. Like he did at United.
Is it possible that Leverkusen will continue the competition with Munich next season?
It's still surprising that Leverkusen hired Manchester United former manager after Xabi Alonso left his position, I never expected it because he is the same manager that destroyed Manchester United. We've seen Bayern Leverkusen perform well over the previous two seasons under Xabi Alonso, but now that the position has been handed over to Ten Hag, we are not sure what will happen next season. Perhaps Bayer Leverkusen thinks Ten Hag is their best option because the manager has a history of winning trophies.
However, Ten Hag first season with Leverkusen may be difficult because most of the key players will leave before the next season. If Ten Hag wants to bring his former player to Leverkusen, I think he should help Manchester United by signing Onana as their goalkeeper. Manchester United would love it if he can get Onana out of the club, as they are going to sell him after failing to win the Europa League.