Why was Relational() extention method removed in .net core 3?

The syntax has been changed a little bit in EF Core 3 according to this issue, here is the new version:

Pluralizer pluralizer = new Pluralizer();
foreach (IMutableEntityType entityType in modelBuilder.Model.GetEntityTypes())
{
    string tableName = entityType.GetTableName();
    entityType.SetTableName(pluralizer.Pluralize(tableName));
}

foreach (var entity in modelBuilder.Model.GetEntityTypes())
        {
            // Replace table names
            //entity.Relational().TableName = entity.Relational().TableName.ToSnakeCase();
            entity.SetTableName(entity.GetTableName().ToSnakeCase());

            // Replace column names            
            foreach (var property in entity.GetProperties())
            {
                property.SetColumnName(property.Name.ToSnakeCase());
            }

            foreach (var key in entity.GetKeys())
            {
                key.SetName(key.GetName().ToSnakeCase());
            }

            foreach (var key in entity.GetForeignKeys())
            {
                key.PrincipalKey.SetName(key.PrincipalKey.GetName().ToSnakeCase());
            }

            foreach (var index in entity.GetIndexes())
            {
                index.SetName(index.GetName().ToSnakeCase());
            }
        }