They usually provide the night package (socks, eye mask).

Last night on AUH-FRA I've got that night package without request and later the amenity kit (including another night package), also without requesting it.

Until know I've thought, that they provide an amenity kit on flights with a flight time of more than 6 hours. But that guess doesn't match to your experience.

Anyway it's not easy to find out rules at EY since EY doesn't believe in rules.