Personally, I like the spontaneous wizard as the psion. It puts the finger on what the 3e psion is.There's a negative connotation to Sorcerer or Sorcery, today, because it's used to refer to, in effect (and among other things), con men, who bilk the superstitious by claiming magical powers, too.
But, yes, the definition does imply dealing with spirits, to gain secrets known to them, including magical powers, and to have them do your bidding. The D&D Warlock is closer to a Sorcerer, in concept, though the mechanics still don't much model actually dealing with spirits. Something more like an RQII Shaman, really, would model a dictionary-definition Sorcerer.
Mutant - in the Marvel sense - would almost be more accurate.
Anyway, name aside, the 5e Sorcerer's schtick is, indeed, /magical/ power from within, and that makes it a better candidate for faux-psionicist than wizard, hands down.
While psionics is inevitably supernatural in nature, whether psionics is magical is something that should be left to the DM - and prettymuch requires a new class to package it. Some might prefer the theoretically more consistent 'balance' of keeping the psionic tamped down by the same measures as other casters (Beholder's and anti-magic zones and whatnot), or just the unifying concept that in the fantasy genre the supernatural /is/ magical, while others might prefer adding to the range of supernatural abilities the game models.
Aside from the wizard, I can stomach the bard as a chassis for the psion subclass, better than the sorcerer. Add a suite of telekinetic force spells to the bard list, and the bard makes a fine psion.
(The bard also makes a pretty good shaman.)