I have a booking from EDI-SIN in November and tried a dummy booking for the flight I am booked on, just to see if it was possible. Obviously I didn't complete the booking and an hour later got an email from QR, asking me why I hadn't booked and telling me seats are selling fast. I responded that, as a tourist, I could not enter Singapore and they directed me to the Singapore Government website, which told me just that. My flight is still showing as departing on the due date.