The plan is not to close down TXL now ( they would not be allowed to re-open as it operates with an special permit ) but to merge all civil operations in SXF, the old east german airport besides the newly built BER. No big deal with only about 20 flights a day... Only government/military flights would be still be operating from the TXL airport but they would not use any of the known civilian facilities there but the old french military section of the airport which is still in use today. This would allow them to re-open TXL if needed, who knows there might be problems with the new BER