AMEX issues cards in most countries using the local currency as base currency and local bank accounts. While the theory of having a FB AMEX card in all these countries is simple, the practical implementation is costly and make me strongly doubt that it can be a reasonable plan for AMEX. IMO they might extend the FB card to a few other countries, but not to most or all countries where they have an AMEX card.

Let's take the example of Thailand with AMEX cards accounting in Thai Baht and a separate AMEX legal entity. AMEX offers standard AMEX cards with Membership Rewards (MR), plus cards with TG ROP (just like it offers general cards and FB cards in France). The TG card differs from the standard card by the various (lower) insurance and services provided as well as by the mileage reward scheme. Introducing a specific FB card would imply a separate and somewhat-costly process, while it would have few clients. One should not underestimate the legal, marketing and administrative costs involve in setting up a new card with different features. While many of the functions can be shared with the other AMEX cards of the country, some cannot. Not worth the expense and trouble for such a small market of FB members.