Contrary to the answer in the linked question, let me propose that Sneak Attack does not have a type of damage because there is no type specifically mentioned in the text.
Not all damages must be written
See this answer on the type of damage caused by the loss of blood, as well as some examples in the universe of non-typified damages: the drain of the Agitator Blood, the Bearded Devil's Glaive and the Devil's Tail with Horns. Some types of damage in D & D are not typified and do not conform to the predetermined types.
Sneak Attack only says that you inflict extra damage, without a mentioned type
The text of Sneak Attack says only this:
Starting at the first level, you know how to subtly attack and exploit the distraction of an enemy. Once per turn, you can inflict additional 1d6 damage on a creature you hit with an attack If you have an advantage in the attack roll. The attack must use a delicacy or a weapon from a distance.
You can reason that, just as the loss of blood over time does not have a well-defined type of damage, you can argue that the additional SA damage comes from the exploitation of the distractions and the weak points of the target, which does not it's a problem. Type of damage well defined.
This tweet states that all damage has a type., given by Jeremy Crawford himself. This clearly shows the intention behind the types of damage. However, his tweet is directly contradicted by the Monster Manual, a central rule book, by showing the cases of damage they do do not It has a type of damage.
Keep in mind that these instances are not errors because they are not in the errata. We stay with the designer who declares the design intentions that are contradicted by a central regulation. The rulebook is more authoritarian than a tweet, that's why it's a nucleus rule book
Without JC's statement that all damage has a type, the view that a damage does not have a type is stronger.
You can not choose the type of sneak attack damage, since it is an untyped damage on top of your normal weapon damage dice.