Is it possible to create and save related data in an entity constructor?

Question

This article describes the possibility to have constructors in entity types as of Asp.Net Core v2.1.

And I thought, could it be possible to automatically create some related data upon creation of an entity without writing any code for it in the controller?

Something like this:

public class ProjectTask
{
    public ProjectTask()
    {
        // Somehow check if we are creating a new ProjectTask.
        // if (create)
        // {
        Notifications.Add(new ProjectTaskNotification
        {
            IsSent = false,
            ProjectTaskId = Id,
            Task = this,
            TimeBefore = new TimeSpan(7, 0, 0, 0)
        });
        // }
    }

    public int Id { get; set; }

    // Some more properties...

    public Member TaskOwner { get; set; }
    public List<ProjectTaskNotification> Notifications { get; set; }
    public Project Project { get; set; }
}

And then I would simply save the ProjectTask-entity in the controller, without having to worry about Notifications:

db.Add(projectTask);
await db.SaveChangesAsync();

Can it be done? I don't know either C# or EF all that well, so maybe I'm missing something obviously basic?