A popular contemporary definition for art is "If you define art, you limit it to less than what it is."
In other words, it's been "smurfed". The term has no limiting definition. If I call it art, it is art. If you say it isn't, it isn't.
What I posted was more about the language and ideas within which historically art has been discussed. Art doesn't require the concepts of this language, but demanding something be art can often shrink our ideas and conversations to these particulars and I don't care for that. Ditto for narratives.
your first definition smells like a double edged sword. being advisement not to think limitedly, and being a cop-out that someone can claim that crap is art.
On your second statement, I suspect the second half "If you say it isn't, it isn't" isn't applicable. I think if anybody thinks it is art, it is art. Once raised to that status, its stuck there, regardless of what a naysayer says.
In any event, I mean everyone of my D&D sessions to be a work of art that entertains, moves and impresses my players. I have always done so. Is this art?
I asked my wife, a trained art person. Her answers trended toward subjectiveness on the nature of the session. A really good GM's game could be art. I asked her if every thing you make in art class is art. She said no, thinking of color charts, and even disagreed on assigned subjects(where the student is told, draw that apple). She did seem to agree that if the teacher tells me to draw the apple, and I'm so good it looks great, then technically, it's still art.
Which gets me thinking to a different tack. When did everything become Art. If you take an art appreciation class or art history, you look at sculptures and paintings. Stuff you hang on your wall or put on a pedestal.
At some point, everything else became Art, too.
In this vein, Performing Artists aren't. They are rappers, singers, vocalists, musicians. They aren't artists, they are performers, and we migtht refer to their trade as an art, it's no more the Art than competitive Magic the Gathering is a Sport.
If my suspicion is right, there's some point in time (and i suspect the 20th century) where before that, art was paintings and stuff, and writing was fiction, music was music, and theatre was theatre.
If I can nitpick that D&D isn't a game because it lacks a definitive winner/loser competition trait, than it also isn't Art because you can't put it in a museum.