They might be confused as to what they're supposed to be in front of the cameras. Are they MC even though its been proven they have no romantic feelings for each other? They can't be "Monday Siblings" after the last six years. They can't even really be the ex-Monday Couple, because MC didn't end with a break up or one of hem moving on. Compare now to when news of SJH dating her CEO came out. When the news of the CEO first appeared, KG acted like an ex-boyfriend, who got drunk and mourned the end of his love line. The whole exes thing defined SJH and KG's dynamic in RM for awhile. In this case, however, their relation ended because of a brain scan. How are they supposed to act now? What is their relationship? "Lifelong friends" as they said in the 300 episode? That's not an interesting relationship to viewers. The captions in this episode could even be seen as the editors falling into old habits because they don't know what MC is anymore. Perhaps the editors were at first all aboard the"no MC" train, but after the 300 episodes where MC returned, the editors are a bit less clear on the "no MC" thing and are going back to their old habits where KG and SJH are a "couple". What else do they call MC?