The name is fine but that item may be in the wrong category. If the item came with a game, was available separately or is a promotional retailer type thing, the item should be in accessories. It should only have a game entry if the item was sold at retail with that slipcover, or if the game with that slipcover was found inside of some larger box like a limited edition.
The only types of "display box" type things that are allowed to have separate entries in a game category are licensed rental copies, such as the Swedish Mega Drive games.
But it does seem that these were sold this way at UK retailers with the sleeve over a sealed game. You can find a retail picture here:
https://i.redd.it/1sachem0pzk31.jpgBut the thing is all of the ones on Ebay have the "For Display Purposes Only" and there is no barcode and no actual
sealed ones that I can tell. So unless we can determine whether these covers seen on Ebay are not the actual retail covers, then these entries can stay in the game category.