I think when Arteta understood they were going to play against Bayern Munich he was very unhappy because for Arsenal, Bayern Munich is a nightmare and usually Bayern Munich was the team they could easily beat Arsenal.
The last game they had was a friendly match in which Arsenal won the game with a 2-1 result. But other than one friendly game, whenever Arsenal was playing against Bayer Munich in the Champions League they lost the game with a 5-1 result and that's too much for them.
Now once again Arsenal should stand against Bayern Munich while they don't have good memories about the past games they had, I guess we are going to see Tuchel and his players win this match against Arsenal as there is more pressure on Tuchel because not being in the first place of the table in Bundesliga. maybe this can be a good motivation for them to beat Arsenal.
In my perspective, when I see Bayern Munich against Arsenal, I am not happy because it will be extremely difficult for Arsenal to get the chance to overcome Munich in the Champions League. This odd they give arsenal if the match is close now they will give arsenal a big odd more than Bayer Munich, since arsenal are facing Munich they have not had the chance to defeat Munich, but I don't know for this season if they will have the opportunity to defeat Munich, in terms of experience and quality arsenal will be defeated because Bayern Munich used to qualify for the Champions League every season and Tuchel is a very talented coach more than Arteta because Tuchel win more trophy more than him.
Am just waiting for this match arsenal vs Bayern Munich because I can't predict anyone now, because odd deceive something so I will let they should play the first leg before someone can know the real club that can win the game and qualify to semi finals this season.