Index Usage Stats Bug Fixed in SQL Server 2012 SP2 CU12 / SP3 CU3
Microsoft has just released a new round of cumulative updates for SQL Server 2012, and the release notes indicate that a fix to the sys.dm_db_index_usage_stats dynamic management view has been included in these updates. This is good news for index tuners using SQL Server 2012.
As of SP2 + CU12 and SP3 + CU3, SQL Server 2012 will persist index usage information even when ALTER INDEX REBUILD is run.