It looks like the upkeep of CP Tango will now become a joint responsibility:
South Korea and the United States have tentatively agreed to push for the joint use of a key U.S.-controlled wartime command bunker complex on the peninsula in a move likely to incur a new financial burden on Seoul, informed sources here said Wednesday.
The allies have been discussing how to manage CP Tango, or Command Post Theater Air Naval Ground Operations, in Seongnam, just south of Seoul, during their talks on the Status of Forces Agreement (SOFA) governing the legal status of some 28,500 American troops here. Washington initially hoped to hand over to Seoul control of the decades-old bunker ahead of the envisioned transfer of wartime operational control (OPCON) after which South Korea will lead wartime operations with the U.S. playing a supporting role.
Seoul had balked at the idea of solely managing the bunker due largely to hefty costs for repairing and upgrading its facilities and equipment. Currently, it does not pay for the command post management, but a deal to share the bunker would mean Seoul footing part of the bill.
You can read more at the link, but according to the article, CP Tango was established in 1974 and was recently put on a list of budget cuts to fund President Trump’s US-Mexico wall. This joint funding of CP Tango appears to be some kind of attempt to save the bunker. I guess we will see what happens.