It's too early to know much. But it seems that every year there are guys who have too slow of 40 times at the combine or Pro day, or a bit too small, or something that doesn't precisely fit a profile.
Then they turn around and become very good NFL players. It's not that speed doesn't matter. But.... speed in shoulder pads, cleats and a helmet is different than speed on a track surface in shorts and running shoes.
And... instinct, smarts and play making ability can't be measured in those showcase days.
Another guy teams are going to be slapping their foreheads over passing on is Van Jefferson because he's not fast enough. Yeah right. He's not only fast enough, he is already an elite route runner, understands the game in a way few rookie WRs ever will (even some vet WRs might not understand), and gets separation that the fastest of guys can't always get because there's way more to separation than speed. It's reading the Dback, quick feet, and technique at the NFL level because the DBs are fast, too.