I still hope for the day when someone will come up with a universe (model) where ordinary matter inside the Hubble sphere stays constant. My reading of the first paragraphs of this article went that way.
However, following the line upwards we learn that the entire observable universe – the area that sits within the “Hubble radius” is also on that line.
Unfortunately, baronic (energy//matter) is escaping from this Hubble sphere. At the present time we don’t know (or don’t have) a good mechanism to replace it. Even worse if the first law of thermodynamics applies then we won’t find such a mechanism.
As the universe within the Hubble radius has grown in size, so has the total mass/energy thanks to increasing dark energy.
So, on the other hand, the increase of dark energy seems to violate this first law. I still hope.