There has always been a charge when using the card overseas or incurring a foreign currency transacton. Until recently all that was provided was a single converted amount but this included the 2% or 2.99% charge. Amex have decided (or were forced) to show the charge separately and thus provide some transparency to their fees and charges. If you check the exchange rate used you should find that it compares very favourably to using cash or the awful travelex.

It does not of course compare well with the zero cards but you do have to factor in the miles accrued and decide for yourself if the extra costs if worth it.
I have had 2 premium plus cards for years and play them well getting 2 BA/Amex 2 for 1 vouchers a year which allows me to take the family away incomfort at least once a year.

A pet hate however is that this card does not get you out of the BA £5 charge per ticket per passenger when booking dircetly with the airline. Recently bough 4 seats to Germany and had to stomp up £20 for a transaction completed entirely on line and with e tickets. This worked out at 5.5% of the fare costs and seemed utterly disproportionate. Nor is it waived when if spending several thousand pounds on a club or first ticket.
BA have a lot of issues to resolve and this is just one but for the moment I would prefer they kept flying.