I'm not really sure whether it matters if the Packers attend a school's pro day or not. GM Ted Thompson is watching film, and has detailed scouting reports already, on all the players they might be interested in.
Gil Brandt has a good update from all the pro days going on this March. It's not surprising to see the Packers attend it for Kansas, along with every other NFL team, because it's worth taking a look at star CB Aqib Talib even if there's zero chance he'll fall to the Packers. Plus you learn that all the teams go to Oklahoma not just for the players, but for the great barbecue.
Since I'm a homer, I did find the review from Wisconsin interesting:
Players ran indoors on a very fast Astroturf track. There were 14 NFL teams in attendance. On the same day that Brett Favre's retirement news was breaking, Packers GM Ted Thompson still made the trip in person. One Badger who did not work out was CB Jack Inegwuono, who is set to have a knee operation ...
" DL Nick Hayden (6-3¾, 292): Had a 32-inch vertical jump, 9-foot, 3½-inch long jump, 7.33 cone drill, ran position drills and stood with everything else he recorded at the combine.
" WR Paul Hubbard (6-3 ¼, 223): Ran the 40 in 4.42, had a 39½-inch vertical jump, 4.05 short shuttle, 7.12 cone drill and ran position drills.