I can think of two reasons why Raptors might not get priority. First they are not fleet vehicles. There are surely some big fleet orders that Ford doesn't want to delay, only the customer to switch to Ram or Chevy. Sure, some the Raptor owners may do the same, but will likely be a bit more patient.
Second, the Bronco customers have been waiting a lot longer, and think Ford needs to get those on the road more than they need to get Raptors on the road.
I'm not saying that Raptors are not important, or that they won't possibly get chips before every fleet or Bronco vehicle is made. I just think they cost of delaying the Raptor could be a lot less than delaying many of the other models.