It would be an interesting experiment for someone who has never seen the OT to watch TFA.
It would most likely ruin his Star Wars experience. I would feel guilty simply if I did not try to convince a friend to watch OT first, let alone purposely do some “interesting experiments”.
Someone is bound to drag their non fan boyfriend/girlfriend or relative to see it. You’d have to be living in a cave not to be slightly familiar with the basics of Star Wars. There’s hardly anyone who doesn’t know of Darth Vader or what a stormtrooper is.
And lest we forget, the original film dropped us into the middle of a conflict we knew little about.
Well that wasn’t really the point here. It wasn’t a matter of someone randomly dragging their friends to see it without seeing OT and unintentionally ruining their potential OT experience. You said it would be an interesting experiment to do so, which implies doing it on purpose for the sake of experiment.
And knowing Vader is a “bad guy from Star Wars” is something completely different than experiencing Vader’s character through OT at first hand. The same applies to other Star Wars basics.