Still waiting to find out how the English story is significantly different from the Japanese/French/German story because I haven't seen any sign of it. I know some of it is phrased differently but it's still the same story under the phrasing and doesn't suffer for the differences.
Maybe it would help to go into detailed examples of the differences between translation, interpretation and localization.
Here's a phrase that used to be heard a lot in English (not quite so much anymore):
Last night, my uncle kicked the bucket.
An older native English speaker is going to automatically understand that it means "Last night, my uncle died".
Someone doing a straight 1:1 translation into another language would translate it exactly as it looks: Last night, my uncle kicked the bucket. As in, my uncle took his foot and kicked a bucket across the ground or into the air.
But that's not the information to be conveyed to the non-English speaker. They need to be told the uncle has died.
Instead of translation, we turn to interpretation so the meaning of what was said is shared instead. Now, there's no misunderstanding on the part of the non-English speaker.
But what about localization? Where might that come in?
In some cultures, direct references to a person's death may be frowned on. You're not going to tell another person that someone died. You might instead say "My uncle is no longer with us". That's localization - changing what was said to be consistent with what is normal/acceptable for the other individual's culture.
Reverse it so the phrase "My uncle is no longer with us" is being spoken by a non-English speaker and translated 1:1 to an English speaker, the English speaker might respond "He's not? Well where did he go to? Will he be back soon?" Oops. Instead, it gets interpreted so the English speaker understands the uncle has died.
Translation is usually as much interpretation as direct translation because every language is going to have its colloquialisms that the translator has to work around. That's why we don't always get exact 1:1 translations and why localization is sometimes needed for concepts that simply do not translate and cannot be interpreted well.
On the subject of Haurchefant's spicy nature in JP and FR (don't know about DE) but not EN, that's easy enough to explain. The primary English speaking nations are still constrained by a rather Puritanical background where other nations aren't. His JP characterization fits easily into French culture. It doesn't in American or British culture, where such forwardness is expected to be done in private. That's why he was localized.
Was the game or Haurchefant's role radically altered by the localization? No. So why obsess over it?
Some posters in this thread need to go back and read the linked Reddit post that has the direct quotes from members of the localization teams on how the process works. To summarize:
The JP story team writes the story (the filler lore is still overseen by Oda-san). They share it with the EN localization team, that checks for what would need to be altered because a JP concept used may not work well in other languages. The JP team then reviews the EN feedback and makes adjustments. Eventually the teams working together with a final version of the story that will work in all localizations, even if phrasing and some characterizations have slight alterations.
There are not different stories for JP and EN. It's the same story. You're not going to get 1:1 translations because of differences in the languages but it is still the same story.
It would be fun if someone fluent in both languages could give us direct 1:1 translations (not interpretations) of dialogue from important story moments so we could see the results (and also to see just how accurate Google translate is with its 1:1 translations).