I don't believe that Bayern Munich will be able to remove Arsenal from the champions league this year. Arsenal is no longer that fragile team they used to be. Arteta has succeeded in transforming this team, that they are now a threat to any team they face. The game is very much balanced, Bayern is having a poor season domestically while Arsenal are having a wonderful season. This clearly makes Arsenal the favourite team to win and qualify.
I also think that Arsenal is no longer a fragile team like last season because they themselves can definitely learn from what happened to them last season so that Arsenal can improve it this season. Although I also don't consider Bayern Munich a team that has failed this season because Munich is only behind Leverkusen in its own domestic league and no other team has been able to surpass Munich so far so the meeting between Arsenal and Munich in the Champions League quarter-finals this season will be very interesting to see.
Arsenal's strength has improved a lot at the moment and this is in contrast to Bayern Munich, which has experienced a slight decline and their inability to maintain consistency this season means this match will be difficult.
Mathematically, based on what happened last season, Bayern Munich will be slightly favored in this match, but if you look at the strength, I see there is a chance for both teams to qualify for the semifinals.
Arsenal are far better than Bayern Munich this season but only that doesn't cut it because the two teams have a history and I feel their is a way Bayern can also utilize that so no matter how bad Bayern have been, arsenal shouldn't forget that they are a big side and it takes just one change of atmosphere to make a team be in very spirit and change their playing style so arsenal and arteta should be ready for the best and still accept the worse.