Hello asimha,
Thanks for the warm welcome!
You were informed correctly by my colleagues in the Service Center. The regulation regarding the advance seat reservation on the A340-600 was implemented for overwing-exit-seats on February 4, 2010 . The federal aviation office decided that all four exit seats in this row must be occupied. In general, emergency seats can be reserved by status members, though. To abide the federal regulation, advance seat reservation for all passengers had to be put out of action – therefore these seats are only accessible upon check-in 23 hours prior to departure. Please understand that this is out of our hands and we are sorry that we cannot offer the usual service here. I would recommend you to check in as soon as the flight is available, so that you can still get your preferred seat.
Best regards,
Isabell