Well yeah. I suppose for a really long track it could help to learn it. But in my experience you won't get the really important information (braking points, braking zone stickyness, turn in points, apex speeds, etc) from a game. You can learn where the track goes but there is no way you'll ever be able to refine your lap to the point of going out for the first time in real life and setting a decent time.
Yes, if you don't know a single thing about driving race cars I guess you could learn something. But time spent on the actual track is about a thousand times more effective as a learning aid. When I first got on the track I learned twice as much in one lap as I learned in years and years of playing racing games.
For instance I can learn, in a video game, that a track goes left right left right right right after a few laps, and then refine my braking and apexes, but as soon as I hit the real track all that will go out the window because the track will be different (subtly), conditions will be different, etc. it only takes one lap to learn where the track goes.
Let me put it this way, if I had the choice of running around the new Thunderbolt raceway for 10 minutes in any car or take 10 hours of track time in GTR2 for an upcoming race, I'd choose the 10 minutes of track time.