Can it actually happen? If Astral Power is technically Arcane, can it still charr a corpse to ash?
Because if it can, I do have a backstory for a Worgen Balance Druid that literally goes around cremating Forsaken and Gilnean bodies with the power of the most benevolent God/Entity in WoW so far.
This is a game mechanics vs. lore thing. In game mechanics, astral power is arcane as a spell school, but in lore it’s just lunar magic. So, in the world of WoW, yes. You can burn someone with the power of the moon. But it’s not the arcane doing it. It’s just the fury of a deity.
If it does, then the head-cannon of cremating a corpse with the moon is actually logical, which means the Harvest Cremationist would actually sound rather interesting than having a boring 'ol Fire Mage that kind of stinks at cremating the Undead (ironically).