That is my understanding. I see it as emphasis and simplification of the message.I imagine the subtraction and exclusion of the irrelevant is part of what you both mean by filtering
It strikes me that painters (and sculptors) have a fundamental advantage over pre-Photoshop photographers, in that they can cut and choose from several scenes with great ease. Paint a sheep based on the sheep in this flock; paint a background that suits; and eh presto, one great painting of a sheep in situ. The painter is doing exactly what you refer to: "subtraction and exclusion of the irrelevant" plus some compositing. The compositing is the additive bit and the most strikingly different to photography, but it's hardly recent. It strikes me that they must have been doing it since the age of cave paintings (hand + arrow + buffalo = dinner).
If you're going to make a case for photography being different (inferior or superior) to painting or sculpting, compositing is a good place to start. Hence all the noise about the camera not lying. Playing around with Photoshop (and other software) has the potential to blur the division. Is that a good or a bad thing?
Traditional modernism has had to pare down non-representational cues and visual elements. Working with abstracted ideas was a novelty. Photography can do as much, easily.
I've read it a few times that a picture can tell a lot about the photographer. I am more inclined to think you need a collection of pictures so you can see what's common, what's different, and build a picture of the man (or woman).
Apparently not...(or do I just lack a sense of humour?)
Charles