Arteta described Anthony Gordon’s winning goal for Newcastle in the 64th minute as an “absolute disgrace” after his side lost 1-0 at St James’ Park.
Arteta said the decision was “embarrassing” and that he felt “ashamed” by the standard of officiating in the Premier League.
Arsenal then issued a statement in which they supported Arteta’s comments and called for officiating in the top-flight to improve.
Arteta has now revealed that he did not know the club were planning to publicly back him and has thanked them for their support.
“It was great from my point of view, I didn’t expect it,” said Arteta.
“I said it’s my duty to stand in front of you guys and give what I think and then the club has got many options, and they decided to do that one. I really appreciate it.
“I think the players did, everybody at the club did. It showed again that we are one and ready for anything that comes across to fight it in the best possible way.”
Arteta said he has not had any contact with the PGMOL or referees' chief Howard Webb, but that the club have.
“Me, directly? No. The club I’m sure they’ve been in touch and it’s probably more up to them to discuss that topic,” he said.
Arteta stood by his comments when quizzed about them again on Tuesday and believes the injustice will unify the squad.
“Well, there is a really bonded team and club at the moment,” he said.
“Certainly, it shows the unity, the way we acted to express externally how we felt. And we have to do that.
"And we want to transmit what we want to do, you have to speak loud and clear and put yourself in the line when it’s needed and this is what we’ve done.”