Bayern Munich did not make the wrong move by releasing Lewandowski from their squad, because apart from Lewandowski having been at Bayern Munich for a very long time, in the end the team also needed younger players to be included in the Bayern Munich squad. And besides, Bayern Munich can still dominate the Bundesliga, although it will be a little difficult for other leagues such as the Champions League.
It is not bad at all. They did not want to break their salary ceiling as well as strategy for old players. Decision was made le Lewandowski go and they have Mane as a replacememt that is good on paper. Mane is younger than Lewandowski and even if he lose this season, I think he can have a better contribution in next season. In additon, Bayern will have more time in next summer transfer to find another striker for their team.
Bayern are very disciplined with their management for transfer and finance that helps them to be a greatest club in Bundesliga and one of most successful clubs in Europe and Champions League.
In essence, with Bayern Munich being able to maintain its dominance in the Bundesliga at least that is good enough for Bayern Munich, because basically to dominate the Champions League is of course a difficult job. Because even though Bayern Munich still had Lewandowski at that time, it was still difficult for Bayern Munich to win the Champions League title and moreover this season Lewandowski was no longer in the Bayern Munich squad.
So yes, basically whoever the players Bayern Munich have, at least they still have a big chance for Bayern Munich to dominate the Bundesliga, because one of Bayern Munich's successes is that they have good management.
At least with management that is divided and can be maintained for a healthy finances, then Bayern Munich will be fine in the Bundesliga every season.
What's more, if in the upcoming transfer market Bayern Munich recruits another forward, then of course that will make Bayern Mnich have a better attack and maybe also be stronger for competition in the Champions League.