An update from the Washington Post:
Washington Post said:The transition team for President-elect Donald Trump asked the head of the D.C. National Guard to remain in command throughout Inauguration Day after media reports that he would leave in the middle of the ceremony created controversy, the Guard said.
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As is customary for presidential appointees, Schwartz had offered his resignation after Trump was elected. In an interview Friday, Schwartz said he learned he would be replaced on Jan. 20. He said the transition team ultimately asked him to stay in the job for a few additional days, but only after the report of his departure had been published Friday on The Washington Post website.

Schwartz said he turned down the transition teams offer because, by then, he had begun packing up his office and notified his staff. He said he believes the offer came only as a result of the negative attention his departure attracted.