Lewandowski is a perfect transfer for Barcelona and they will have an amazing offense this season. Bayern Munich now needs to search fast for a good striker so they can replace Lewandowski. Also Ibrahimovic is still injured and wont recover for a long time so i still dont see what kind of contract they can offer him.
Barca lacked a proper striker and signing Lewandowski completes that now. With Lewandowski gone Bayern have already started searching for his replacement and they are targeting Konrad Laimer from RB Leipzig. About Zlatan, reports were that it will be a short term contract extension or most probably a one year or at most two year contract extension will be offered to him.