https://en.wikipedia.org/wiki/Directed_evolution
...and this means directed selection is not an natural process by definition. natural evolution doesnt proceed toward a defined end, [bipedal primates with large cerebrum] [or from highly lethal-->moderately lethal-->nonlethal]
virus do not start from day one as very lethal and become progressively less lethal over successive replications.
communicability is an advantage to host to host transmission. breaking linkage between traits allows differing selective factors to act on these traits.
when a virus doesnt kill you or make you ill until after you have infected others then that virulence is not subject to the same selective factors as it previous partner [communicability]
It's a matter of degree, not a binary thing. You can't be 100% sure of anything, but as long as people are aware of something and act accordingly, there will be selection pressure. Reduced social contact has an effect regardless of whether specific carriers are identified.
I don't know what that means or what your source is. It sounds like you're maybe saying that orthodox evolution theory doesn't apply when humans are involved. Why, what is the mechanism?
And how exactly do you get from the idea of a pathogen evolving to be less virulent to "artificial" selection? Stipulating that somehow artificial selection is different, what would make it artificial? It seems obvious that human behavior would factor in, but what is the definition that makes the evolution artificial?