This is an event intended to hook up players to possible endorsements, now or more likely down the line, an off-field job fair if you will. Sponsors will be assessing personality and filing away impressions.
Which players would be most attractive to sponsors, do you think? Fantasy stars, which means offensive skill position players. Who's on the list? Except for Bosa, they are all QBs, RBs, WRs and TEs. Who did the Packers draft in the first 2 rounds? Not those kinds of guys.
The closest you get to a question here is, "why isn't Sternberger on the list"? That's not much of a question.
You are right. No cause for concern. Its like a speed dating event for endorsements.
Back when I was into card collecting I read that this was one event where card companies would pay the rookies to wear jerseys so they could cut them up into little pieces and put them in cards and call them "event worn' jerseys. The players changed jerseys many times throughout the course of the event.