The arrival of Noni Madueke has indeed shifted Leandro Trossard's position. And that was predictable. But honestly, I personally believe that Leandro Trossard is still very much needed in the Arsenal squad. However, I wouldn't blame Arsenal if they ultimately had to let him go to a team that wanted him more. And Bayern Munich is currently interested in Leandro Trossard. So, I think it would be quite good for Leandro Trossard if he moved to Bayern. Furthermore, I believe Leandro Trossard is a versatile player. So, he won't be slow to adapt to another club when he leaves Arsenal.
However, whether he's appropriate or not is still difficult to say. While Trossard's role is sometimes needed, he's not Arteta's first choice. So, it's not a question of appropriateness, it's just that perhaps letting him go wouldn't be a major issue for Arsenal's overall performance.
If Arsenal doesn't end up selling him before the window is over he should see Madueke's arrival as a challenge to work hard and fight for his place, Martinelli did that when they bought Trossard to he can either work hard to get playing time or end up being sold during the winter, well u think Arsenal might still keep him for the time being to strengthen their depth.
Yeah if he leaves it won't show any weakness in thar position since there's still Madueke and Martinelli to fill up for him, if Bayern Munich are really Interested in him them it would be tough for Arsenal to keep him, with a fair offer they'll let him go to strengthen other areas, not a bad idea.