This was only about ensuring defenders have to defend the entire field to open up space for kelce and Juju. The biggest thing about having a consistent deep threat like tyreek was that defenders were forced to shade coverage to him. Mecole does not have the consistent ability to get open deep so you still need that. MVS does and when teams played the Packers with him on the field they also had to account for this. So while you can't replace tyreek, you can force coverage to account for a consistent deep threat which limits what they can do elsewhere on the field.