I don't see how this could possibly apply to so called sems sde texts. The rhetoric of "bodhicitta" in sems sde is identical to that found for example in the Guhyasamaja.tingdzin wrote: Guenther was also of the view, which I happen to share, that Dzogchen is rather anomalous to Indian Buddhism.
Second, we have no evidence whatsoever of any thögal like teachings being written down by anyone until the early 11th century, whether Buddhist or Bon.
In terms of unique doctrines, the most unique thing in Bonpo Dzogchen is ZZNG's emphasis on sounds, lights and rays, which really only figures in the ZZNG, and it pretty much absent from other Bonpo Dzogchen cycles, based on a electronic word search conducted on the other two main cycles of Dzogchen in Bon.
While I would have no complaints about sourcing Dzogchen in Central Asia, within the sphere of Indian cultural influence, I see absolutely no evidence which links Dzogchen doctrines with teachings generally outside of Buddhadharma and the Indian context.