No. They never had the opportunity to oppress us. They never established themselves in Africa like today. Admiral Zheng got his fleet shut down with the quickness by the Ming. We don't know what could've happened if they had the opportunity to set shop in the continent like now with africans opening all the doors. Also, Africa was not that weak. Today, we don't have the equivalent of the Mali Empire.
Plus, this is a weak argument. Back then, China didn't know capitalism. The way they were seeing the outside world was different from today. Since, China, like Japan, have seen capitalism and european colonialism.
Japan was an isolationist country, then they modernize and turned into turbo expansionist. This is not the Ming dynasty.
Also, China has a long way to go before it becomes a "service economy". We'll never know the true intentions of the Chinese until they start moving, in a direction or another.
The only solution for african is starting to make african countries stronger in order to avoid/reduce any threat. Africans can't build a policy based on the good faith of the chinese' elite. It's naive.