I thought of this a few years ago and wasn't surprised that it had already been hypothesised. I'm not an academically trained physicist, but I am a decent mathematician. I'd like to start off by stating that the cosmological constant problem is one of the most severe fine-tuning issues in physics. Quantum field theory predicts a vacuum energy density that is vastly larger (by up to ~10^(120) orders of mag) than the observed dark energy density responsible for the accelerated expansion of the universe.
Recent results from the DESI survey show a mild preference for dark energy that changes over cosmic time rather than staying perfectly constant.
In my paper https://github.com/mikalnolan/entropic_gravity_research/blob/main/Dark%20Energy%20from%20Dark-Dimension%20Modes.pdf you will read a narrow, testable phenomenological framework in which dark energy emerges from Kaluza-Klein graviton modes living in a compact extra dimension known as the "dark dimension." Our cosmology is realized as the distant, nearly flat region of a generalized McVittie geometry that contains a higher-dimensional parent black hole. We emphasize that our observable universe is not claimed to sit inside the parent black hole's horizon.
The current size of the dark dimension is fixed by matching to the observed dark energy density today. The novel ingredient of this work is a specific postulate: the radius of the dark dimension evolves in time proportionally to the square root of the parent black hole's horizon radius.
Using the time dilation between an interior observer and the parent geometry's coordinate time, I derive the resulting effective dark energy equation of state. This leads to a clear, falsifiable prediction relating the dark energy " equation of state" parameter to the possible running of Newton's gravitational constant through the five-dimensional Planck relation.
I work throughout in the nearly de Sitter regime relevant to current observations. Important limitations of the model - including the need for a deeper derivation of the running postulate from bulk physics - are stated explicitly.