4. Potential midfield vacancy
It has been reported that Thomas Partey could leave Arsenal this summer and if that happens, there will be a gap left in the midfield. Jorginho will most likely be a squad player next season so he won't be the one to fill that role on a consistent basis.
Smith Rowe played in the midfield in all of his appearances this season so it is very possible he could be the one to replace Partey, albeit a more attacking replacement.
Arsenal is rumored to be after a midfielder this summer, so could save themselves some money with an option already available to Arteta in Smith Rowe