One possibility you hadn't considered...

QS has been asked/told to tidy any loose ends before their UID permanently falls silent.

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I have a working theory certain users have been asked to clear out their desks, or, choose just one alt to go forward with.

TMAN ...LAUDA  and a handful of other profiles (I'll let people speculate endlessly which ones they are) and that it's QS' turn to logout for the last time.