To be fair, this is not the first program opt-out to be hosted by Amazon’s preferred Survey Provider, Qualtrics; there have been several other similar situations over the last 6 years or so.
We ourselves haven’t received this notification as of yet, but I simply used our friend @dwat0870’s URL, allowed it to refresh back to the simplified default URL (often, links like these are SoA Account-specific, but Qualtrics’ automated mechanisms typically figure that out quickly, and reset to the landing page itself) - and had no qualms about entering our Merchant ID/Token, as I’ve done so many times before.
One thing I did do, however, was to save that landing page, after I’d entered the token (but before I clicked the ‘next’ arrow), as a .mht file; did the same for the ‘completion’ page, because our friend @GGX is correct about Amazon ‘losing’ things:
Ya never know when Amazon might ask for proof that you actually did this or that thing.