Basic idea is that if the creator of the job updates the due date an email is automatically sent to all people who have accepted the opportunity. Or give people the option to opt into sending those automatically when date is changed and/or allowing bidders to opt out of receiving auto updates if they are attached to the job at a high level.
I believe that currently the GC is responsible for sending a message with the update which seems like a menial task that could be missed. If sent with a special email tag like "Project Timeline Update" or something it would be easy to sort into a folder in your email.
