I should've been slightly clearer with the above, sorry. Here's a more accurate breakdown:
Filigree roll entirely separately.
The named loot table (nonweapon) comes up at about the same rates as recent packs.
The weapon table also comes up at about the same rate as recent packs, but you cannot get both a weapon and named loot on the same roll.
The drop rate of the nonweapon loot isn't diminished due to the existence of the weapon table.