Fire can be broken with a sword in creative

I'd say works as intended. You can put the fire out by clicking on it with anything you can carry, or even your bare hands.

Creative mode takes this a step further by extending this to any type of block, except lava and water.

Is this any different than putting out the fire with any item? Can't honestly tell from the description. All I could get when I tried to replicated was the intended fire extinguishing behaviour.

Affects 19w13b. Since this wasn't marked as Working as Intended by a Mojang employee: can you give evidence as to why this is a completely intentional feature? Swords are supposed to not be able to break blocks in creative mode, so the fact that they can break fire blocks is almost certaintly not intentional at all.

Affects 19w14a

Affects 19w14b