If it were me, I would write an add-in to do this. The Submit for Approval transition would set a variable 'Submitter' for the document and the add-in would look for the state changes to 'Released' or 'WIP' and notify the submitter by reading the value of the 'Submitter' variable and sending a message to them.
I have an add-in that would work for you. You're able to notify a user, group, or a user specified in a variable, all with an HTML notification that supports file variables. Reach out to me for a link to the product. Thanks.