The reskinned stone slabs (thats what they are) aren't hacked items. As far as i'm aware they were obtained in vanilla, and then Mojang added a proper wooden slab, leaving the "alpha slabs" without any texture. If you DO consider them "hacked items" then add infinity + mending bows, because they were obtainable but are now impossible to make.
Bedrock, barrierblocks, and pig spawners can all be placed with an exploit iirc. I know spawners will disappear after the chunk is unloaded, but I am not sure about the other 2.
A command block was once found in the end (alledgedly)
Ghast spawners were and probably are still a thing (none may have been stored properly in shulkers though, so they might be impossible to obtain but still out there)
I probably forgot about a couple others, but yeah this article has quite a bit missing.