fill_player_head UUID hasn't updated to new UUID format

nbt for player_heads given using /loot with the "fill_player_head" loot table function still contains a string form of the UUID (hasn't updated to integer array format)
e.g.
{SkullOwner:{Id: "374c2f0c-690c-40dd-94a2-c3291b6688e5"}}
As opposed to {SkullOwner:

{Id:[I; 927739660, 1762410717, -1801272535, 459704549]}

}