As long as you’re sticking to classical physics, the fundamental laws are invariant under time reversal. So in what sense are forces “irreversible”? Take Newtonian gravitation, an example you use. If you take the time reverse of a world where massive particles interact according to Newton’s law of gravitation, the resulting time-reversed world will also be one where massive particles interact according to Newton’s law of gravitation. The fundamental forces do not pick out a direction of time, so how can they be the foundation for the entropic arrow of time?
This is probably not what OrphanWilde wanted to mean with his statement, but I agree with you that it does seem incorrect the way it’s stated, (classical) forces are indeed symmetric in time. As it’s written, it looks like the increase in entropy is caused by the various forces defining an arrow of time. Instead they’re more like two faces of the same medal: we see the forces operating in one time direction and we see an increase in entropy in the same direction. The same laws for the forces, with a reverse arrow of time, would cause a decrease in entropy. So, once you pick a preferred direction for the arrow of time, the laws for the forces dictate how entropy should evolve, but they don’t choose the direction of the arrow for themselves.
This is probably not what OrphanWilde wanted to mean with his statement, but I agree with you that it does seem incorrect the way it’s stated, (classical) forces are indeed symmetric in time. As it’s written, it looks like the increase in entropy is caused by the various forces defining an arrow of time. Instead they’re more like two faces of the same medal: we see the forces operating in one time direction and we see an increase in entropy in the same direction. The same laws for the forces, with a reverse arrow of time, would cause a decrease in entropy. So, once you pick a preferred direction for the arrow of time, the laws for the forces dictate how entropy should evolve, but they don’t choose the direction of the arrow for themselves.