I did not see a consensus at all. I saw, and still see, a significant amount of Arsenal fans wishing they never sold him.
Seems to me he had a split 'love or hate' following at Arsenal.
Our social feeds were inundated with Arsenal fans taking the piss at the fee. Look at the comments to when David Ornstein broke the news;
Sure, a good number will of course wish him well;
.... he's an academy lad, but the Arsenal consensus was very much that they got a great deal for him and it was time for him to move on.
A bit like when we sold Anichebe. Fans of course wished him well, but were laughing at the fee West Brom paid.
Back to my original point - a very simple one really which the manager himself said when he signed - he has to improve from Arsenal, particularly with goals to improve us - obviously - hopefully a new environment/setup will see him really kick on.