If this transition takes place, then in my opinion it will be a super strange acquisition. With all due respect, he is not a top player and will never be one - why is he in Bavaria? I do not think that Bayern will "shrink" and make weak transfers. They need a top striker and at a young or at least promising age of 25 - a maximum of 27 years.
First of all, they lost Robert Lewandowski. Then after that, Choupo Moting seems to be playing quite decently. Even though he was not able to fill the void that was left by Robert Lewandowski, but he was at least trying to do what his team needed him to do. I do not know if Füllkrug will be able to produce what even Choupo Moting was producing. This has been a very sad situation for Bayern Munich. They wanted to improve their attacking capabilities by bringing in a competent player with the money that they got by selling Robert Lewandowski. But that plan absolutely failed.
With the money that Bavaria received from the sale of Lewandowski, it is impossible to buy anyone at all who would correspond to the level of Bavaria. But Bavaria has no shortage of money and can afford much more expensive purchases and I hope they accept this reality that the "cheap" options have run out. I think that Füllkrug is just a cheap option that doesn't fix anything. If you make a purchase, then it must have some meaning.