I've looked at 16 different hides so I guess it's true for all of them. The description in the item info window is using this template: This is the hide of a mob_name. It can be refined to leather using a Tailoring Material Refiner. Since we don't have tailoring refiners anymore, perhaps it should read: This is the hide of a mob_name. It can be refined to leather using a refiner.
Yeah, you'll find that the Item Descriptions like that were done before the various refiners were scrapped in favour of just the one refiner. I believe it happened around the same time as seismic bombs and separate ore/enmatter were dumped as well... If anyone else spots other IDs that need updating like this one, post them here and I'll point the devs to the thread.