Let's not be fooled here one of two things are happening. Either it is a trick to get followers or they mistakenly "downgraded" a 4.3 rom that already had the insecure boot loader and are trying to figure out why it won't work again. There is no reason why the haven't put up the links already. I'm betting its a trick but who knows? Deep down inside I hope they figured something out.
MobileTechVideos is a very renown website and Josh Groce is a very respected developer. He wouldn't try to "trick" anyone to believe something like this isn't true. Also, there is a reason he wouldn't put up any links because this wouldn't be something that can be done on the software level. It's most likely a hardware mod and requires JTAG.
Could he have been mistaken and jumped the gun on this announcem ibly. However it wouldn't be something as simple as not realizing the phone already had an insecure bootloader. He knows what he is doing.
To get a taste of the stuff he does check out some of his youtube videos. Here's an example: