Thank you for asking that, I had been looking for an answer to whether that theory is likely or not.
I skimmed a study on avalanche deaths. The very few people who actually died from physical trauma did have familiar sounding symptoms - facial abrasions, rib fractures, skull fracture. But the vast majority of deaths were caused by asphyxiation. Of the 56 cases studied, only three people died from physical trauma alone. Asphyxiation killed the rest of them.
Of the four people found in the ravine, their causes of death was listed as rib fractures and internal hemorrhaging for two (Dubinina and Zolotaryov), skull fracture for one (Thibeaux-Brignolle) and hypothermia for one (Kolevatov). An avalanche that caused these deaths would be relatively unique, as it caused massive damage, but covered them with so little snow that they died from their wounds before asphyxiating.
Of course, that is based on the assumption that the medical examiner can distinguish between death caused by wounds and death caused by asphyxiation. I know nothing about autopsies, I can't say.