Developing countries aren't going to be too happy about this. If a large number of a country's citizens adopt this, it forces that country to lose its independence over monetary policy. Since Libra is not controlled by the local government, this is not a fixed exchange rate regime, it's effectively dollarization and can have far reaching consequences.

IMHO, the Libra is at the same time too ambitious (in aiming for full capital convertibility across nations) and too timid (in entirely giving up monetary independence). A libra-usd, Libra-euro, libra-inr, etc. which allows countries to retain monetary sovereignty would have been easier for governments to accept. But then, Facebook can't say it's a new currency and circumvent KYC and other local regulations. But who knows? Stranger things have happened. The euro is a currency without a state. Maybe the time has come for denationalizing money.