yes, from a medical standpoint it's not great that he is still in the protocol but it's not terribly bad either.
Most individuals are experiencing concussion symptoms for about 10 days with 80% recovering within 14. A small percentage of people report sx past the two week mark and that is more concerning.
Since he experienced his concussion on a Sunday, but didn't show sx until Monday, or was diagnosed Monday, the fact that he is about 10 (now 11) days out and not practiced is not terribly bad. I was able to get the nfl's concussion protocol from Dr Kevin Guskiewicz, who is a member of the nfls head neck and spine committee as well as one of the writers of the national concussion guidelines. I don't have it off hand but when I was at this conference I was surprised any nfl player was able to pass this within one week and play the next. It's quite restrictive. He needs to be 2 or 3 days removed from symptoms to be able to practice I believe.
If he doesn't practice at all today then I would be more worried than I was yesterday. If he doesn't go today I would expect him to be out Sunday. Friday is the really pushing it
Edit: after going through my information from his presentation I remember he did not give us the protocol because it is privileged information, or whatever. Basically it's owned by the nfl and he cannot just give it to us in a hard copy. This was also the case regarding concussion statistics he was showing us in the nfl. But I do believe one criteria for just returning to light practice was 2 or 3 days removed from any sx, and then I believe they need to show no signs of sx for two days of light practice to be cleared for contact. Basically the way he laid it out is that the only way possible for a player to return the next week is if they are one of the few that recover very quickly. Most of the time you're looking at least one week off. I'd be very surprised if Williams played this week without practicing today.