My understanding is that voter registration data is a matter of public record in most (all?) states so the idea that it wouldn’t be a matter of public record north of the border is itself odd to me.

Being on the electors list is optional, is something you can opt-in to (and opt-out of), and is not required in order to vote in Alberta.

There are many reasons an individual may choose to not be on the list (eg. domestic abuse situations).