According to Puckpedia, Vegas now has 24 players on their active roster (14 forwards, 8 defensement, and 2 goalies). The only play that can be sent down without waivers is Holtz, who certainly won't be sent down.
You have to think that they will be sending a forward on waivers before the season starts. I would have to think it will be one of Pearson, Schwindt, or Lavoie. I didn't pay much attention to their camp, but maybe Olofsson as well.
My hunch is that they wanted a depth center and claimed both Schwindt and Lavoie, but didn't think they would get both. I wouldn't be shocked to see one of them back on waivers right away.
https://puckpedia.com/team/vegas-golden-knights