I'm pretty positive they were available a year ago to the States.
Also, I've flown S class on my non-mileage-earning "special" corporate fares. Biggest scam since my CX corporate fare costs more than SQ's corporate fare and SQ (which is arguably one of the stingiest mileage programs out there) gives full Star Alliance mileage credit on theirs.
CX's getaway specials might also be in S class. I don't bother even checking anymore since they don't earn miles and availability is always limited.