I don't think they are friends but they could play together once again without problem.
Aurier has never insulted or offended Zlatan just said he was not scared of nobody, including Zlatan
Zlatan used to give nicknames to his teammates and I know Aurier was not very happy to have been nicknamed 'Bamboula', a term that could be viewed as racist term.
Trapp was called 'Adolf'
Di Maria was called 'Dumbo'
Verratti 'Spaghetti'
Pastore 'earthworm'
Rabiot 'Maman Rabiot' because his mother is his agent
Blaise 'Banania'