Have you every tried to place an order with BFL in BTC? It takes you to Bitpay which immediately converts your BTC into USD and pays BFL in USD at the current exchange rate. So these claims are bogus.
You don't know that. Even if Bitpay pays out their merchant in EUR or USD, the merchant can still opt to convert some of it into BTC for the long term.
So Bitpay has no option to pay out the merchant in BTC? Seems like a lack of service...
Bitpay can convert BTC to BTC, but whats the point? BFL could just accept the BTC whien you select that payment option on their website without paying a fee to Bitpay. Bitpay exists to convert from BTC to something else.
The following is not a diss toward BitPay, for I like them guys, but the service CAN be used as a mixer of sorts, having the coins first sent to them as payment for a product/service, then either have them set their, convert to fiat, or sent to you via some other wallet.
I welcome BitPay to deny or verify the above, for I'm not 100% sure, and don't want to be spreading FUD of their good name.