List does not implement IBindingList so the grid does not know about your new items.
Bind your DataGridView to a BindingList<T> instead.
var list = new BindingList<Person>(persons);
myGrid.DataSource = list;
But I would even go further and bind your grid to a BindingSource
var list = new List<Person>()
{
new Person { Name = "Joe", },
new Person { Name = "Misha", },
};
var bindingList = new BindingList<Person>(list);
var source = new BindingSource(bindingList, null);
grid.DataSource = source;