No, Leverkusen don't look weak this season, it's just that Munich aren't as weak as last season. Munich have some quality players and that's why it's hard for Leverkusen to compete like last season.
We can't deny that Leverkusen is weaker in this season. Meanwhile Bayern Munich becomes stronger under Kompany's management. Regarding the squad quality, I don't see significant change. It is only about the decline of Leverkusen performance. Other teams in Bundesliga may be improved their performance, they also may know better Xabi's tactic. So they can deal with Leverkusen game this season.
When it comes to the upcoming season, I'm honestly a little skeptical about Ten Hag. I don't doubt the coach but I'm worried that Leverkusen will lose their best form.
Ten Hag is actually one of top coaches, he also won some trophies already. There is nothing wrong with his quality as a coach. I think we don't need to underestimate him. Let's see first how he can manage Leverkusen in the few early matches next season. Now, it is not the right time to judge him!
Certainly the departure of some crucial players in the team would have a negative effect on the team but if Ten Hag and his team are able to sign the right players they could even further strengthen and improve their squad to be good enough to battle for the league title next season.
So far, only Jonathan Tah is leaving the team. It is because he doesn't get a contract extension. However, there is no big problem because Leverkusen has enough players in the defense line. As far as Florian Wirtz stays in Leverkusen, I think Ten Hag still can expect for the competitive team. But the problem is Florian Wirtz seems to leave. Ten Hag must be ready to sign a new player who can be the right replacement for him.