China’s foreign minister demanded meeting with Justin Trudeau - The Globe and Mail
"Sources said the meeting was both a show of courtesy and an opportunity for Mr. Trudeau to raise the case of Kevin Garratt, a Canadian missionary who remains behind bars in China awaiting sentencing after being tried on charges of stealing state secrets. Mr. Trudeau wanted to tell Mr. Wang it would be difficult for Canada to embrace China’s hopes for a new so-called golden era if it continues to hold Mr. Garratt."
Based on my experience in the diplomatic service, I don't think it is too unusual for visiting officials to make a courtesy call on host country official one rank senior to them. That being said in the Chinese system the Minister of Foreign Affairs is a relatively junior function as the key players are members of the Poliburo of the Chinese Communist Party. Wang Yi is just a member of the Central Committee.