This is mostly a concrete example of something that I thought of in another thread: Gauntlets of Ogre Power can be used by Warrior, Rogues, and Priests, which in the PH, is everyone but Wizards. But then Psionics Handbook added the Psionicist group, and whether or not they could use them (or a plethora of other class-restricted items) is never addressed, to my knowledge.
I appreciate you observing this. This is too often overlooked: which class can use which magical item. Even in publications focusing upon magical items, often they are not labeled which class can use which item.
I would venture to say that Gauntlets of Ogre Power would not work with psionicists.
I default to an item can be worn/used by anyone specified able to use it, or that anyone can use it so long as not specified they cannot. Maybe there is an old Sage Advice column from Dragon or Dungeon which adjudicates this in some official capacity