Not really. There are many places EY flies from (in code-share) that are not on the list - TXL, FCO, KRK to name a few and it seems unlikely that online check-in is not posible for flights from any of those airports. EY website clearly says online check is is possible for all code-share flights. I even called the airline and they said it could still be possible via direct link from "Manage my booking" tab but I just wanted to make sure.