Most teams don't want this honor or exposure as they focus on the season, so, I imagine 'Merica's Team drew the short straw.
NBC Sports Edge wrote:
The Dallas Cowboys were selected to appear on this season’s five-episode series of HBO’s “Hard Knocks”.https://www.nbcsportsedge.com/edge/foot ... erry-jones
Dallas will become the first team to be featured for the third time on "Hard Knocks", last appearing under Wade Phillips ahead of the 2008 season. Dak Prescott, recovering from a dislocated right ankle and compound fracture suffered in Week 5, will likely be the main attraction after the team went 6-10 in coach Mike McCarthy's first year. The first episode is scheduled to air Tuesday, August 10 at 10 pm ET.