You don't have to update statistics after rebuilding indexes. When you rebuild an index SQL server also rebuilds it's statistics. Since it reads all the records in the table, the statistics will be based on all the records and will be very accurate. If you update the statistics after that, SQL server will read only a sample of the table and you'll have less accurate statistics.
I have to admit that I don't remember if SQL Server 2012 has the alter index statement. If it does, then you should consider using it instead of DBCC DBRINDEX statement which is going to be removed in the future.