The Saints were running a linebacker at him at the beginning of his routes to add an additional cover. They were trying to stop the inside pass plays where Beasley moves the sticks and force Dallas to beat them on the outside. This was schematic and not something Beasley is doing. Or Dak, for that matter.
But as Dak begins to make those outside throws and turn them into completions, the defense will need to adjust. Add the fact Elliott is now actually being incorporated into the passing game and it will be sacrifice an extra player to beasley or allow Zeke to get the ball at the second level with a full head of steam, and sometimes with two huge angry men as blockers.
Take a deep breath. This is the chess match the coordinators are playing. it will evolve.