In theory? Sure. But this is not something that can be guaranteed - it depends on how value is being exchanged. When the majority of the users assess bitcoin's value on the USD and there's a lack of bitcoin-exclusive productions, then you can safely say that unless bitcoin can propel itself on its own feet (and drop A LOT in price), it is a fiat currency.
Bitcoin is consumable so it doesn't actually qualify as a fiat currency. Independent of its USD exchange rate it can be used on the Bitcoin blockchain regardless of third party support. People seem to dissociate bitcoin as a digital object and see it merely as a tradable unit of currency.
Yeah, that's a feature and it can be used that way, but is its price being justified by that alone? No, it isn't. Most of it comes from it's price relative to the USD which basically tethers it to the USD.