Well it's a fact, Bayern does need a new attacking partner, for me this has many variants, if Bayern had hired CR7 things would look different, because despite everything CR7 is an athlete, CR7 has no problem with help in the defense or cover any position besides that he can resume a game at any time, apart from that he would have been a good friend of Muller, they still have time to acquire him, Mane is very good, but if they can help with someone who is like CR7 I think that Bayern would assure there if a UCL, it would not be bad, but what the managers think is something else, and everyone has to stick to that.
Attacking partner? Bayern needs a pure CF. Yes, Ronaldo is one of the good options for CF position. But considering Ronaldo is 37 years old, I am not sure that Bayern management will try to sign him. Bayern may try to sign a younger CF like Harry Kane. Although it is difficult if they really want to sign Kane because he is the main player in Tottenham. While if they want to sign Ronaldo, I am sure Ronaldo will agree. And it should be easy for Man United management to let Ronaldo goes because Ronaldo is no longer the main player there.