This is about the yuan not the euro. Devaluation doesn't make it easier to pay debt. It helps foreign countries to pay down dollar denominated debt more easily. Meanwhile, the DXY is structurally way higher than average right now. The USD remains very strong compared to historical exchange rates despite its recent drop.
Exhibit 1:
The US Dollar devalues against the Euro.
Some claim that is Trump‘s plan to make easier to pay the US debt.