I just checked again and you're right! You'll just have to believe me when I say that I had checked (obviously) before posting, though I did, on that occasion, search CDG-SIN. But now both that and FRA-SIN are available. This rather bears out the rest of your post - maybe they have just released award availability in F, now that they are more clear about what might sell in the meantime.

Either that or the website gives mixed results and you need try to several times. I was rather surprised as it only offered seats in Economy and there was not the usual note about their being no availability in Business or First. The choices simply did not appear.