Correct, the file type was named to sound like the peanut butter as described in the documentation, “Choosy developers choose gif,” because the name is a pun. The word “jif” means a short amount of time. “I’ll send it to you in a gif” is a play on that similarity.

But like many technical terms, more people were reading the word than using the word, and people don’t read manuals. Then for whatever reason some fake liguists made up some bullshit rules for pronouncing acronyms, and that argument took hold.

Whatever the reason, the hard “g” pronunciation has caught on, and is now also an acceptable pronunciation.