This just doesn't pass the smell test to me.
Other apps they've pulled (for various reasons -- no of which were outright stated), they've just done it. No heads up to the developer, nothing. So why set a deadline to when it was going to get pulled? Doesn't make sense.
Because for the other applications, Apple pulled them off for their reasons. I Am Rich was a "judgement call" by Apple.
However, Apple did not pull Tris from the App Store because technically, it's not entirely clear whether it does violate the patent (remember, games cannot be copyrighted, only patented).
Therefore, Apple probably simply emailed the developer stating that the Tetris Company was unhappy, that's it. The developer can either pull the app from the store, or keep it in there are fight a legal battle.
Aurora Feint and Friend Book were pulled because of breach of privacy. PhoneSaber was pulled because of
trademark infringement. Those are clear cut reasons. But since a game can't be copyrighted, and tris never used the name Tetris, it's not really Apple's call (well, technically it is, but Apple's not like that).