Well, if they are doing it again, they obviously haven't given up on you yet but it does sound like just part of their routine, just checking to see if anything has changed. I imagine you will get reviews every 3-7 years then, from what they say on their website and from what you have experienced. Don't know if any laws or procedures have changed in the 7 years; I'd maybe call them and ask. It's probably a bit like income tax where they keep tweaking stuff back and forth.

With the Sequester and all this mess going on now, who knows how long it could take. It's a numbers game for SSI, where the State administers it and they get X amount from the Feds based on how many people they need to service and how big the state is, etc. whereas SSDI is Federal/Social Security run so you don't have to worry about other disabled in your state, just the Federal Government and what it might be doing, the ijits in Congress.

A redetermination is when they start from scratch, look at everything all over again, rather than just to see if there's any changes. Sounds like you just have a review, as you read/thought.