Doesn't matter. The game came out when it came out. The rating should stand. I've literally only seen this type of shyt done as frequently as its done with video games. No other form of entertainment does this type of shyt on the scale these video game reviewers do it. It takes the value away from the original rating.
This happens all the time in films, critics change how they feel about films a lot. Movies that seem good but don't stand up to repeat viewings.
This is why I hate number ratings because it's hard to simplify these things into numbers when they're more complex.
Gears of War's rating is lowered because it's a relatively simple and mindless experience that was defined by its crisp gameplay for the time but feels dated because games have pretty much built on that experience while offering loads more.
Hell, Vanquish and Binary Domain are two perfect examples of games that built on that cover combat style to make it more engaging and making Gears of War a little more dated.
A kid, now, that had never played GOW would probably thinks it's a pretty fun, action packed, and likable experience but there have been games that have done the cover combat (3rd person) better, games that have done the emotional and character sides better (Spec Ops and the Last of Us), and so forth.
It was a 9 when it came out but it's like 7.5 now. If Goldeneye was released today, same weird control scheme and graphics, shyt would get roasted because more I'd expected.