I think updating review scores is fine, but wouldn't it get problematic fairly quickly? How long are you going to follow these games? Will you change the score of an MMO to 0 once it's shut down? Will you halve the score of a sports game when it's online servers are shut down? Will you update the score every time there is a major outage or problem with the game?
While I would appriciate seeing an up to date status on a game such as the life of online servers, the stability, or if its still supported with pathces or updates I don't really think review scores is the way to go. I think this would be a great feature for GB. If we had a section on every game saying the current status of the product then that would serve this purpose well.
The thing I have a problem with however is reviews based on a product which doesn't exist. Reviews of games which isn't a representation of what the costumer can buy is down right misleading and should be illegal. It would be like reviewing a deluxe super special edition of a car and then using that as the basis of the cheapest and most basic model out there. Reviews should *never* be fixed in stone before a game is actually out and the reviewer has hands on the actual product they are reviewing.
It starts getting into weird territory though when games fundementally change down the line, such as the removal of the fast forward feature... Perhaps one could do a re-review down the line in some cases?
If polygon wants to keep an up to date score of the game as it is every single time, thats fine with me, but I'm not sure I'd call it a review, it would be more like a status tracker of some kind.