I think what the OP is asking if anyone has ever seen a non-impaired proof coin that came from a proof set (not any matte proofs like the special issue 94 and 97 Jeffies and the 98 Kennedy) within the last 20 years that would have a "PR" grade (e.g., PR65, PR66, etc., and not an "SP" or "specimen" grade), but lacking a cameo such that the TPGs would not give a CAM, DCAM, or UCAM desigation to it.
My guess is that it's possible, but highly unlikely. Looking at numismedia.com, their price listings for proof lincoln cents list 1978 and later coins with only a "Deep Cameo" designation and list all 1971 and later with at least a "Cameo" designation. So it's almost as numismedia thinks such coins don't exist.
Brings up an interesting question whether such a coin without a cameo designation would be considered a rarity and bring a premium.