I was at 491k and top 10% this morning. No emblem. Checked Collections, several vendors, inventories. Nothing. I recall the old 10% emblem, Glory's Claim, had a similar issue. Difference being it was a Bungie Reward that could be redeemed at the end of Guardian Games if you were in the top 10% for all three weeks. Problem is the deadline to redeem was also at the end of the games, so it just disappeared. They ended up having to manually give it out at a much later date.