Hello,
I think this is not possible. I need the same behaviour, but alfresco don't support this. When you set the launch date or expiration only an aspect is set. There exist dome bean called at 3:00 and this bean goes throught all repositories and when find a content with launch date expose them to the bashboard.
Please correct me I it is not true.
The solutions is (I think) to write own bean and connect to the deployer.
Thanks Mila