If you read the article (I know this is Slashdot) they explain that MWI is an Intel-only SMART attribute. They use different SMART attributes for the Kingston and Samsung drives.
This SMART attribute starts at 100 and decreases as the NAND's rated write tolerance is exhausted. It's completely unaffected by the number of reallocated sectors, and it's been ticking down steadily since the experiment began. The remaining life estimate in Intel's SSD Toolbox utility is based on the MWI, and so is the general health assessment offered by HD Sentinel, the third-party tool we've been using to grab raw SMART data.
On the HyperX 3K, the SSD life left attribute tracks flash wear. Like Intel's media wearout indicator, it counts down from 100 and is tied directly to the rated lifespan of the NAND.
The wear-leveling count is sort of like the MWI and life-left attributes on the Intel and Kingston SSDs. It's "directly related to [the] lifetime of the SSD," according to Samsung, and it bottomed out after 300TB of writes.