This article seems to be making the claim that the Libra blockchain will not be viewable by anyone other the validators. This is counterintuitive - even if only

This article seems to be making the claim that the Libra blockchain will not be viewable by anyone other the validators. This is counterintuitive - even if only validators can confirm new blocks I expected the chain would be public, there would be explorers, etc. Does anyone know if this question has been answered somewhere definitively?