I have stumbled across "Alpha N-key rollover" in US Cherry catalogs, but I'd say it's marketing BS (it's applied to all their boards from the lowly G83 upwards). The term might be in agreement with what IBM used to specify (I think the Model M was also considered "N-key rollover"), but it doesn't have anything to do with true NKRO capability. The matrix is merely routed so that collisions during typing are avoided for the most part. Should be an IBM-style matrix.
BTW, in the rubber dome world, rather basic models often have pretty good key matrices while their fancier illuminated and partly even "gaming" cousins have a "cost-cutting" matrix. The same happens with key feel.