All cast members have annual revolving contracts that guarantee them a certain number of episode appearances.
The contracts are flexible, and the actor can negotiate time away to be written into scripts to allow for outside work, or simply a break - so it may be that the actor concerned is having some time off and will return. Anything other than a death can mean a return eventually - if the actor and the producers are willing for the character to come back.
Oh perlease...actor. Male..actress female! I wonder why 'Sally' is in prison, cast iron 'evidence' notice quotation marks....how can she get off with it mounting against her? Waiting to see how it goes.....not holding breath with soap saga's but will be interested to see outcome!