Yes I believe so, they did revert for many people, this is $200 off of any trade in. Later they changed the offer details but they did honor the trade in offer price for many people who sent in some $30 Walmart phone etc.
Either way there is a high probability that Samsung (3rd party dealing the trade in), may reject the trade in with some stupid reason but you may have to follow up a bit and I believe eventually you will get the $425 off as long you sent the right phone in and in decent condition as described. Remember this is also a special offer for the Note 7 owners, so Samsung hopefully is careful here and wouldn't want bad press after what happened to Note 7.