There are reasons guys walk-on at linebacker. He needs to grow an inch or two and likely get faster. At his size, he should be a safety, but a listing at linebacker probably means that the overall foot speed just isn't there. That can change. Some guys just need a couple of years of focused training.
As for how he is doing, he is well down the depth chart. Most of the LB positions are filled by seniors with 3 or 4 years of playing time. There are a couple of versatile true freshman on scholarship who will likely play immediately at the Mike and LEO, when Wilson is not in there and Edmiston needs a break. The STAR position is stacked with Whitfield, Cannon and Reeves all contributors you would be comfortable with in that position. The WILL spot is filled by the most experienced and respected player on the defense at any position and is backed up by a guy that the coaches gave special recognition to for having a great spring.
In short, absent devastating injuries or miracle performances for each of his limited reps in practice, it is unlikely that Landon will see the field in 2017. Stranger things have happened though. Didnt Linscott play a couple of snaps as a freshman walk-on? I can't remember.