In general, someone with the skill to handle a hard piece of music will be able to learn it regardless of whether or not they've previously learned an easier arrangement. In most cases where someone who has learned an easier version finds a hard version frustrating, the problem is simply that they lack the skill to handle the hard version, and starting with the hard version wouldn't help.
The key think to watch out for is that while some "easy" versions do a very good job of preserving the key musical aspects of the piece (especially rhythm), some versions simplify them so much as to change the fundamental character of the piece. As an extreme (hopefully hypothetical!) example, if a rendition of "Don't mean a thing if you ain't got that swing" were to replace the "doo-wop" section with thirteen equally-spaced notes, someone who got used to that as being how the piece goes might be stuck thinking the actual correct version seemed "weird". This may be countered by ensuring that a person is familiar with how the real version of a piece should sound before they try to play a simplified version and, in some cases, by encouraging the person to play correct rhythms whether or not they are actually notated.