Rabicano usually displays as roaning around the flanks (sometimes in stripes along the barrel) and a skunk/coon tail. I see none of that on this horse. If anything, he's a grey sabino (possibly combined with other patterns).
No rabicano. The flecking is because the horse is turning gray. Eventually, the colored patches will blend in with the already white area and you'll only be able to see where the patches are by the different colored skin under the hair.