If we assume that Mata Nui's AI doesn't differ much from that of the average MU inhabitant, then I suppose those viruses could potentially be used on any MU being to bring about the same effect? I.e. putting someone into a coma from which the being dies eventually?
This would only insofar be more useful than assassination/poisoning or something in that regard in that except for Miserix and Alternate Teridax no one would have the means to do something against this virus while wounds can be treated and poisons countered with antidotes, I guess, though.
Or maybe The Shadowed One with access to viruses can now potentially figure out a way to create his own viruses?
As an afterthought - Maybe the amount of virus you need to affect someone is linked to the size of the target's systems or something such. So enough of a virus to knock out a giant robot could potentially also be used to knock out a sizeable portion of the MU's inhabitants instead? But I'm not sure if this really would be how viruses work.