Temporarily mute notifications for all members until a project is completely built

As several discussed in this thread, I am a project manager. I often will copy a project template and assign 20+ tasks to someone as I build out a project.

Even if I assign all tasks at once, they will still receive individual emails for each task.

I would like the ability to temporarily mute notifications altogether OR consolidate the notification to just ONE notification, even if you don’t multi-select and assign all tasks at once:
“You have been added to XYZ project. You are assigned to 24 tasks and added as a collaborator on 12 tasks.”

It would be great to have an “under construction” mode and when the project is live, send out notifications to all members associated with a summary of their upcoming involvement. Associated tasks would not appear in My Tasks until the project is live.