Caustic and Stormbite, not properly planned?

Since I'm about half way to 64 I'd thought ask this, with Caustic and Stormbite unlocking at 64, they're intended to be our replacements for Venom and Windbite. However, they can't be used before level 64, which has me wondering if these two skills were actually meant to be traits rather than skills? It doesn't make much sense to keep 4 skills on my hotbar that are the same skill, just 2 of them are stronger versions. Does anyone have any insight on this?

The trait at 64 automatically replaces Venom bite and Wind bite with the better versions. When you enter content that's synced below 64 they'll change back to the weaker versions.

They just show as new skills because they want to show you the tooltips easier.