It would be highly unusual, but there have been a few cases where people who had not been charged with a crime were pardoned, including President Gerald Ford's pardon of President Richard Nixon after Watergate, President Jimmy Carter's pardon of Vietnam draft dodgers and President George H.W. Bush's pardon of Caspar Weinberger. President Donald J. Trump pardoned Joseph Arpaio and others after they were charged and convicted, but prior to sentencing.
But aren’t pardons only for those actually charged or convicted?
https://www.justice.gov/pardon/frequently-asked-questions
https://www.mololamken.com/knowledge-How-Does-Someone-Obtain-a-Presidential-Pardon
The Justive.gov link you provided says this:
It would be highly unusual, but there have been a few cases where people who had not been charged with a crime were pardoned, including President Gerald Ford's pardon of President Richard Nixon after Watergate, President Jimmy Carter's pardon of Vietnam draft dodgers and President George H.W. Bush's pardon of Caspar Weinberger. President Donald J. Trump pardoned Joseph Arpaio and others after they were charged and convicted, but prior to sentencing.