He was definitely considered by Wenger in midfield and did well enough at places like Old Trafford to gain some real praise.
I think Maitland-Niles also played leftback for a long spell before Bellerin got injured though, no? He's been turned into a utility man and I can understand if he's not thrilled about it. Sticking 'em at the fullback has always been a convenient way for managers to deal with midfielders they don't have a clear role for. We used to try so hard to turn Coquelin into a rightback too (no other comparison between him and AMN as players), to the point of even preferring Craig Eastmond in midfield because he was more physical. I heard he's playing for Sutton United in the National League nowadays.