In a .NET 8 project using EF Core 8, I’ve noticed that when creating a migration to remove a column from a temporal entity table, several SQL Server-specific annotations are automatically included in the generated migration code. These annotations seem to be redundant. Here is an example:

public class Order
{
    public int OrderId { get; set; }
    public DateTime OrderDate { get; set; }
    public List<OrderRow> OrderRows { get; set; }
}

public class OrderRow
{
    public int OrderRowId { get; set; }
    public int OrderId { get; set; }
    public Order Order { get; set; }
    public string ProductName { get; set; }
    public int Quantity { get; set; }
}

public class AppDbContext : DbContext
{
    public DbSet<Order> Orders { get; set; }
    public DbSet<OrderRow> OrderRows { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("Server=(localdb)\MSSQLLocalDB; Database=EfCoreTest; Integrated Security=true");
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        // Configure temporal table for Orders
        modelBuilder.Entity<Order>()
            .ToTable("Orders", b => b.IsTemporal(t =>
            {
                t.HasPeriodStart("PeriodStart");
                t.HasPeriodEnd("PeriodEnd");
                t.UseHistoryTable("OrderHistory");
            }));

        // Configure temporal table for OrderRows
        modelBuilder.Entity<OrderRow>()
            .ToTable("OrderRows", b => b.IsTemporal(t =>
            {
                t.HasPeriodStart("PeriodStart");
                t.HasPeriodEnd("PeriodEnd");
                t.UseHistoryTable("OrderRowHistory");
            }));
    }
}

After creating the database I remove ProductName from the OrderRow entity and create a migration:

public partial class RemoveProductName : Migration
{
    /// <inheritdoc />
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropColumn(
            name: "ProductName",
            table: "OrderRows")
        .Annotation("SqlServer:IsTemporal", true)
        .Annotation("SqlServer:TemporalHistoryTableName", "OrderRowHistory")
        .Annotation("SqlServer:TemporalHistoryTableSchema", null)
        .Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
        .Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");
    }

    /// <inheritdoc />
    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.AddColumn<string>(
            name: "ProductName",
            table: "OrderRows",
            type: "nvarchar(max)",
            nullable: false,
            defaultValue: "")
        .Annotation("SqlServer:IsTemporal", true)
        .Annotation("SqlServer:TemporalHistoryTableName", "OrderRowHistory")
        .Annotation("SqlServer:TemporalHistoryTableSchema", null)
        .Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
        .Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");
    }
}

Is the inclusion of these annotations by EF Core intentional? What I can see the outcome of the migration is the same even if I don’t include them.