Received this too.
I wonder if SQ has noticed a drop since they went from 2:1 to 3:1.
Essentially this makes 75,000 points with other airlines worth 65,000 for SQ for a few weeks. Not sure it’s worth it. My usual SQ redemption (AUS-Asia in O) is 93,500 points, so would still be 235,500 Amex...