Skins Can't be Bought With Crafting Metals(?)

https://www.ea.com/games/apex-legends/news/grand-soiree-arcade-event

Based on that, you should be able to buy skins directly with crafting metals just like before, albeit at a higher price point of 2400 crafting metals for a legendary rather than the normal 1200. I just checked, and I can't buy any of the current skins for metals either. This might mean a few things:

1. The skins in the current rotation can't be bought with crafting metals.

2. They changed the details last minute and you simply can't get them despite the website saying so. 

3. There might be a bug going on that hasn't been fixed yet.

In any case, this isn't the first time we've had a direct purchase option for an event. I'd say just to wait until the selection changes and see if you can buy a skin with metals. Please note that the description provided in the link above doesn't say anything about what will or will not be purchasable with crafting metals, so I wouldn't get your hopes up. 

Edit: They added 6 legendary skins to the loot pool of Apex Packs, meaning in the "Loadout" / "Legend" tabs, you might be able to unlock the skin you want there. For instance, the "Modern Advances" RE-45 Skin is unlockable for 1200 crafting metals in the "Loadout" tab under "Pistols".