Let's reword sneak attack slightly to make sense of this:
Sneak attack is the skill or ability of the Rogue find a vulnerable or weak spot on the creature it's attacking. Hitting this vulnerable or weak spot allows the Rogue to add Xd6 damage to the attack.
As you can see this is not a damage type, it's something that increases damage dealt. You don't deal damage with Sneak attack, you add the sneak attack amount to the weapon being used. So the damage is based on whatever weapon you are using at the time of the attack.
Are sneak attack Slashing's damage if made by a sword ?
Do sneak attacks take the type of weapon used ?
For example, is sneaky damage to a demon divided ?
Let's reword sneak attack slightly to make sense of this:
Sneak attack is the skill or ability of the Rogue find a vulnerable or weak spot on the creature it's attacking. Hitting this vulnerable or weak spot allows the Rogue to add Xd6 damage to the attack.
As you can see this is not a damage type, it's something that increases damage dealt. You don't deal damage with Sneak attack, you add the sneak attack amount to the weapon being used. So the damage is based on whatever weapon you are using at the time of the attack.
Yes: sneak attack damage is the same type as the attack. Discussed here if desired.