No, they're right. The devaluation is relative to other currencies, so any debt measured in the devalued currency is now much cheaper when measured against other currencies.

I.e., if a debt is VB1000 before devaluation, worth about USD$100, but each bolizar is devalued by 100, then after devaluation, that same debt is still VB1000 but is now only worth USD$1. The devalued debt is now much easier to pay off.

However, if the debt had been measured in USD, it would now be 100x more expensive to pay off in terms of bolivars.