Emerging markets have reasons to be wary of MMT. They don’t strictly meet its preconditions. While every country does print a legal tender and collects taxes in its own currency, not all can borrow in them. Nor can they allow their exchange rates to float freely, especially if they import vital commodities like food or energy. The degree of economic freedom enjoyed by the governments of the U.S., Japan, or the U.K. is simply not available in most places.
Highly recommended Bloomberg article on the role of MMT in our modern global economy, and why many smaller / less developed countries are wary of copying the same (bad) strategies of the US and Japan.