moses, once banished from Animal Farm, returns. Which piece of information let’s the reader know that the pigs, in fact, approve of his return?

I'm not sure the pigs approve of his return. The pigs dislike Moses’s stories of Sugarcandy Mountain, just as the Soviet government opposed religion, not wanting its people to subscribe to a system of belief outside of communism. Though the Soviet government suppressed religion aggressively, the pigs on Animal Farm let Moses come and go as he pleases and even give him a ration of beer when he returns from his long absence. The pigs do find moses a distraction that occupy the animals without any danger to their power.