Why did Preston feel it necessary to provide this information about the Jaaxs' Thanksgiving?

It is easy to forget that this is a true story and these are real people. The Jaxx family is having a horrible Thanksgiving. Nancy's father is dying and Jerry's family is still in distress over his brother's death. All this underscores the stress these people must feel with the added stresses of a level 4 lethal virus at play. The dramatic affect is that these are people still affected by the stresses of everyday life:their lives are not just about containing a virus.