By saying this challenges the US dollar, it definitely suggests that it's no coexistence.

As the article explains, the purpose of using Yuan is to replace the use of USD:

In Latin America and the Caribbean, the use of the yuan is growing especially “in those countries that are looking to establish stronger ties with China, that view themselves as in some way politically aligned on this particular objective on decreasing their overall reliance on the dollar and on the U.S. in general,” said Margaret Myers, director of the Asia & Latin America Program at the Washington-based Inter-American Dialogue.

The article literally says the intent is to replace the dollar.