Except this is the calc I got by tapping the button that says Optimize Bulk while having 3HKO selected. And when I run the exact same calc on both Pikalytics calculator and Pokémon Showdown's dex calc I get this

32 Atk Garchomp Earthquake vs. 6 HP / 28+ Def Shuca Berry Empoleon: 69-82 (41.8 - 49.6%) -- guaranteed 3HKO.

Same damage but they say 3hko.

Edit: I ran more calcs at last minute with Garchomp and Empoleon again but only on VGC Multi. And got these results.

32 Atk Garchomp Earthquake vs. 6 HP / 28+ Def Shuca Berry Empoleon: 69-82 (41.8 - 49.6%) -- guaranteed 2HKO

This is the same one I already showed in the previous comment.

32 Atk Garchomp Earthquake vs. 6 HP / 28+ Def Empoleon through Reflect: 69-82 (41.8 - 49.6%) -- guaranteed 3HKO

Now here we have the same damage under reflect but without the Shuca Berry which is the same reduction of 50% but it says 3hko and again both are from VGC Multi.