Interesting....I got the $2 from their calculator yesterday, the calculator is down just now when I tried the link, but it says "any tablet" according to this on their website (from the link, emphasis mine, little ad box on the right):
"Trade Up to the New Samsung Galaxy Tab S2
Get the Galaxy Tab S2 8" for $299.99 or the 9.7" for $399.99 after $100 trade-in bonus when you trade in
any working tablet.
In store only. Terms and conditions apply."
Maybe it's evolving as they watch the on-line chatter.