it's interesting the say
oneworld® Emerald members with elite status on Alaska Airlines
, why not just say Alaska 75k members? maybe leave an opening for the upcoming 100k tier?
Anyway, nice find this is new to me. SDC is my favorite elite benefits, sometimes can saved $$$. As for capacity, there is always a chance the confirmed is not available, and you need to standby. Just the way it is. My experience with DL is difficult because they still blocking seats for now. But on AS flights, I don't recall a 100% flights the past few months for either west coast or transcon, but not sure the inventory about SDC either.