Microsoft changed their support policy around the recover of an Exchange database. From now on, any database that has the repair count greater than 0 must be evacuated to be under the support policy.
The database repair process is often used as a last ditch effort to recover an Exchange database when no other means of recovery is available. The process should only be followed at the advice of Microsoft Support and after determining that all other recovery options have been exhausted. For many years in many versions of Exchange, the repair process has largely been the same. However, that process is changing, based on information Microsoft has gathered from an extensive analysis of support cases.
In short, Microsoft is changing the support policy for databases that have had a repair operation performed on them. Originally a database was supported if the repair was performed using ESEUTIL and ISINTEG/repair cmdlets. Under the new support policy, any database where the repair count is greater than 0 will need to be evacuated – all mailboxes on such a database will need to be moved to a new database.
Read more at source: http://blogs.technet.com/b/exchange/archive/2015/05/01/new-support-policy-for-repaired-exchange-databases.aspx