backup chain broken

Environment:
SQL Server 2008 R2, Windows Server 2008 R2, Native-compressed backups.

Objective:
After Migration from ServerA to ServerB, I still want to use the name ServerA by the applications. So I want to rename ServerB to ServerA so that the applications dont have to change. For the rollback plan I want to keep the database on ServerA in restoring mode so that I may apply the logs from ServerB and reverse the role when required.

Test Scenario that works.
1.    Take the last Tail Log backup from ServerA with NoRecovery Mode to keep the database Demo on ServerA in NORECOVERY Mode.
2.    Apply the above backup on ServerB and bring it online.
3.    To keep the ServerA in sync, take the Backup from ServerB and apply those on ServerA.

Test Scenario that DOESNOT works.
1.    Take the last Tail Log backup from ServerA with NoRecovery Mode to keep the database Demo on ServerA in NORECOVERY Mode.
2.    Apply the above backup on ServerB and bring it online.
3.    RENAME ServerB to ServerA so that we can call the Old ServerB as New ServerA for our understanding.
4.    Fails:  To keep the ServerA in sync, take the Backup from ServerB and apply those on ServerA.  This step fails with the error message
Msg 3241, Level 16, State 0, Line 1
The media family on device 'd:\temp\demo_Log3.bak' is incorrectly formed. SQL Server cannot process this media family.
Msg 3013, Level 16, State 1, Line 1
RESTORE FILELIST is terminating abnormally.

Additional Information:
Even the restorefilelistonly and restoreheaderonly also fails on the Old ServerA.  
When I tried to do restorefilelistonly and restoreheaderonly on the New ServerA, it gives information correctly.
My confident feeling is that when we rename the ServerB to ServerA, it causes these log backups not to work on the Old ServerA
Please can somebody kindly confirm the same.