The Packers will begin OTAs on May 23, and during the live practices (which allow the use of helmets, but no pads) we'll get to see the Packers' wide receivers group in action.
Yes, OTAs aren't technically mandatory, so it may not be the case that all 12 wideouts currently on the offseason roster, including Jordy Nelson, Randall Cobb, Davante Adams, Ty Montgomery, Jeff Janis, Jared Abbrederis, Trevor Davis, will be practicing.
However, due to the Packers' offseason workout bonus incentives, many of those players will be in attendance.
In any case, it's a big group of Packers receivers heading into offseason activities, and while Ed Williams, Herb Waters, Devonte Robinson, Jamel Johnson and Geronimo Allison are likely only competing for a potential practice squad spot, the previously mentioned seven receivers all have a legitimate case to make the final 53-man roster.