Even if you watch that, he seems to not have an elite first few steps. That isnt the worst thing bc sometimes the slightly slower guys keep a better base and break more tackles.
Frankly they are measuring something that doesnt matter. Ever see a rb line up in a runner's stance? Hell they should at least make them carry a ball.
This is a great time for him though. Many great backs are 4.6.
He made himself some money. He has some numbers the NFL will love, and lots of great film picking up yards after contact (best in the country probably), being disciplined and actually running the play the coaches call, and actually developing as a blocker (he was sad as a younger player). Hell, even the suspension probably helps more than it hurts bc he has one less year of wear and tear.