Is this intentional?

Some items have "bonus skins" that are packed with advertised items

I believe this has been a thing since Forge items

In yours Belongings you received the Hockey Stick, that item says: Reskins Spear, Fire Staff and Ice Staff, so the hockey stick is 3 items not 1 

Most Spear skins also reskin the Ice Staff and Fire Staff, but aren't listed as skins for the staves in the Belongings section. (I think there's a spear or two that doesn't reskin the staves, and there's the Forge skin for the fire staff that's applied directly to it instead of via the spear, but most ice and fire staff skins are via the spear.) Same for Top Hat skins and the Prestihatitator, and Straw Hat skins for the Rain Hat and Miner Hat. The derived items get skins, but the skins don't appear in Belongings or have their own flavour text, and can only be previewed in the crafting menu in-game.

You should be able to craft the racket skins for the Ice Staff and Fire Staff without them showing up in Belongings, as long as you have the hockey stick spear.

2 minutes ago, CameoAppearance said:

Snip

That's a weird mechanic. But I guess it works, so I ain't complaining. I thought it was worth mentioning, but if that's just how it works then ok.