The federal judge overseeing former President Donald J. Trump’s classified documents case abruptly changed the proceeding’s schedule on Wednesday, reshuffling the timing for hearings on an array of important legal issues.

The move by the judge, Aileen M. Cannon, was unlikely to have much impact on the overall trajectory of the case, but it reflected the substantial number of unresolved legal motions she is juggling. Last month, Judge Cannon scrapped the case’s trial date, saying she could not yet pick a new one because of what she described at the time as “the myriad and interconnected” questions she had still not managed to consider.

Judge Cannon kept in place a hearing she had set for June 21 to discuss a motion by Mr. Trump’s lawyers to dismiss the indictment on the grounds that Jack Smith, the special counsel named to oversee the prosecutions of Mr. Trump, was illegally appointed to his job.

Similar motions have been rejected in cases involving other special counsels, including Robert S. Mueller III, who investigated connections between Russia and Mr. Trump’s 2016 campaign, and David C. Weiss, who has brought two criminal cases against Hunter Biden, President Biden’s son.

The most important change Judge Cannon made to the schedule in a brief order was arguably the cancellation of a three-day hearing that had been set to take place starting June 24 in Federal District Court in Fort Pierce, Fla.

The hearing was originally meant to consider whether Mr. Trump’s lawyers should be permitted access to communications between prosecutors working for Mr. Smith and officials at the National Archives and several national security agencies.