Hello,
I will submit this suggestion for you. Just please be aware that it is unlikely to go through, since, as you mentioned, the event had coupons previously but they were removed, indicating that the devs actively do not want this event to give out coupons, for whatever reason that may be. Most likely this reason is the consolidation of rewards into the sun/moon scrolls system instead of coupons.

However, as I said, I will submit this suggestion for you, and perhaps we will get lucky and it will get reinstated.
Thanks!