Not sure that’s the issue here. I could understand CTD’s when default custom airports interfere with 3rd party content for the same airport, but in the case specifically called out here, Adelaide, there is no MS/Asobo custom airport, therefore nothing to remove from the content manager.
That aside, Xbox does not allow for MS/Asobo content to be removed via the content manager, I.e Zurich, O’Hare, Sydney can’t be removed, only 3rd party additions can be removed (and added)
As it happens, prior to SU7 I had issues with FlyTampa Sydney conflicting with the Asobo custom version (double buildings, jetways etc), ironically SU7 fixed that issue, whereby the FlyTampa version seemed to integrate correctly, however, apparently CTD’s are now a byproduct.