We did, last season.
It had fuck all to do with contracts - he’s taken a pay cut to leave. He wanted out of the club and to return to France. He already said (on his return from injury last year) that had the injury not occurred he’d have left when Wenger did, apparently he was in a right huff when we brought him back in and asked him to play too many games, and he believed that from conversations before he left for the summer break that he had been promised a free transfer should anyone come in for him from France.
And whilst Luiz may also be past his past his peak, at least he’s never crocked.