There’s a huge difference between a slash and a punch. Look at Kaido for the difference. It’s basically combining the two things Gear 5 showed weakest to. Intense heat and slashes.
How does this not fit the narrative? Arlong pulled out a sword, Kizaru will likely do the same.
Rogers a swordsman but he was rivaled by Garp the fist.
Like it’s pretty fitting narratively