Well, I was assuming that by "activation code", that they were referring to their "key" on the COA, which as noted in this thread prior is not used for the initial factory activation of the OEM OSes, those are SLP'ed instead, but the OEM still provides you with the COA and key in case the OS needs to be re-installed using different (non SLP'ed) OS install media. I was suggesting that the "GWA / download-validation" process would: 1) recognize those particular OEM systems (installed using SLP) that are being flagged/investigated by MS, 2) prompt for the "proper" key on their COA, and then the validation ActiveX control (apparently, according to the description), would accept and then re-write the installed OS product-key/product-id using a newly-generated one, after validating using the key off of the COA.
In hindsight though, that doesn't make a lot of sense, if MS is trying to shut down those keys on those OEM COAs, and they have been disabled for online activation, why would the download validation tool accept them as valid, and why would it re-write them with a different valid key and id? Unless to flag them for the future? Ah! At that point, they could potentially confirm that the COA w/key was not "stolen", because the ActiveX control could potentially have access to query the BIOS for OEM/SLP info, while at the same time checking the validity, and the valid association, with the key on the COA as belonging properly to that OEM, and not having been resold off to some non-matching-SLP'ed system. (Aka a white-box build using that "stolen" COA instead of the original OEM box.) By re-writing the product-key/product-id of the currently-installed OS, that would protect it (now that it has been confirmed as a validated OEM system) from being invalidated when the entire block of keys on those "stolen" COA certs are eventually blacklisted.
I may have mis-interpreted this comment though: "This results in a valid code being installed on the system. So, not exactly the most secure process. Even if you have a copy of XP just enter a brand like Toshiba and a store like Amazon.com and the key will be installed on your system." I thought that the person was referring to the installed product-id code, but it may have been referring to the "download validation code" instead, and suggesting a method of "validating" for downloads, even without a valid product-key available to punch in.
I still think that MS could easily start to block out any and all product-keys/product-ids if they wanted to using their "download validation" scheme, which I'm certain is their plan. If they get any of the legislation that they've been pushing for passed, at the state level, they could easily remotely-disable your OS too, legally, if they feel that you've somehow violated their arbitrary licensing guidelines. (Which can change at their behest, even after your purchase of a legal and legitimate OS license.) Hopefully that will never be allowed to happen.