I do not think it is any kind of flagging, since, the tags still exist and are populated by the same games. So if there was a "flaggable" problem, why just garble the ranking. There is no benefit. Also, if we assume there are the same number of players browsing, there should be an unexpected increase in views for other games.
The change many speculate about could be a change in weighting of recurring visitors vs new visitors. There is a difference between a user already following you visiting your game page and a new visitor looking at the game. It is a small data sample, but without considering the game in the OP, three of the games complained about here are web games. Those might have lots of recurring visitors.
Anyways, even small changes could have a runaway feedback effect for some games. Especially if some of the fans were located in the regions with the connection problems I read about in other threads.