Oh! I think I get it! That was the suggested/default grant for beating the Queen of the Moles!

So no, that wasn't a 'Everyone from this point on will automatically be able to access their Gem Weapon from the get-go' grant like Fusion. That was just a 'Default/Suggested Power for if you can't come up with anything' power. Unlocking Fusion at the end of the first event was just a special case to keep everyone from immediately fusing with each other right when the game first started up. I can see where it'd be confusing, though!