When we went in February we asked this question when we stayed at the Disneyland Hotel (or Pink Palace as its known in our house ).
The CM who checked us in said that we would be able to have the Shareholders discount. When we tried to do this at Cafe Mickey, our waiter told us we couldn't. DH asked to speak to the manager (bless him - his nickname in the family is Victor Meldrew ), but no luck.
Don't know if anyone else has experienced this at all.