That's part of it. But it also depends on the voice; for most guitars, it means automatic pitch bend and/or hammer on's and pull offs, and often body/string slap.
In a nutshell, it means voices that trigger 'other' samples depending how you play. It was their response to the complaint that mega voices couldn't be played live (and they still can't, but Super Articulation voices can respond to a similar number of playing techniques, but live). Several saxes the foot switch articulation trigger is breath noise, etc.
