Thankfully Judge Reyes backed off this request at least. For those wondering, a common reason high level DOJ appointees sometimes signs briefs boils down to good leadership. If there is something that is likely to be contentious with a judge, a DOJ leader signs their name on the brief so that any issues someone has with the brief is directed at them rather than lower level attorneys. Regardless, it goes without saying that a decision such as this should not be something a judge is inquiring into.
Just now: Judge Reyes withdraws her request for DOJ to re-file yesterday's submission with any other DOJ attorneys who are willing to sign it. Reyes says she made decision after thinking about it more, consulting with her clerks.