This is correct. A player playing something other than his position will have lowered awareness. The player would have taken the awareness hit anyway had you changed his position (though I think the change position hit is less), but through training, he'd eventually get pretty decent awareness.
For a wide receiver, the two biggest things awareness impacts are
a) Choosing the right option on option routes.
b) Knowing when to break off the route to help out the QB.
So in English, when playing a quarterback in a Wide Receiver, don't
a) Send him on option routes--he'll essentially never get himself open.
b) Use him in formations with very few receivers unless you have a scrambling quarterback who can get himself out of trouble.