The Orpington itself is a heritage breed. As far as the color, I'm not quite sure how long the Lavender color in the Orpington has beed around. @ColtHandorf might know more concerning the color.
According to Google, yes. Orpingtons are considered a heritage breed because they existed before modern/commercial meat and egg production.
Lavender is merely a variety of Orpington. A variety can be more or less common than another, but the color/variety of a chicken does not make it heritage. The birds you pictured are English Orpingtons. It is very difficult to find birds of that quality in the US. Most Lavender Orpingtons don't look a thing like that (see below), just like the bird that Google shows above is not an Orpington.