That is not an update.
That's just a different time.
It's like saying because Roger wore a Strawhat when we first saw him, and then didn't... that Roger never wore a strawhat. It's not an update, it's just a historical fact in the series, he wore a Strawhat just like he used a gun.
I think you've mistaken update for retcon. It's neither an update or a retcon. It's just a different time.
Doesn't matter.
Ed War and God Valley don't contradict each other, they're different times.
Simply means he had a gun at Ed war and didn't at God Valley.
Doesn't change the fact he had a gun, and we can't say Roger isn't also a sharpshooter.
Your logic here is like saying Shanks had 2 hands 20 years ago, but doesn't have 2 hands now, therefore, it's an update. It's not an update, just 2 different times.
Well.... I disagree, but each to their own.
You don't have to agree, I believe Kaido and Chinjao suggested it especially when saying the Pirate King is the person with the strongest King Haki user.