Is the eventual heat death of the universe due to the expansion of the universe? I am reading about the accelerating expansion of the universe and something struck me. The observation that things further away were accelerating away faster and that early observations made it look as though we were situated at the center of the universe.

Specifically, it seems as though the universe itself is expanding and not that the things within the universe were moving away from each other. Instead it seems as though the expansion itself is creating more space between the contents.

Recently I also saw an amazing video on the eventual death of everything in the universe. This seems weird to me because as I understand it energy and matter don't go away they just change.

And it got me thinking, what if this eventual heat death of the universe is simply this expansion eventually ripping everything apart until every particle simply is to far apart to interact.

Basically, as things progress the expansion will affect the contents of the universe even down to the particle level.

Is this the case? Or am I misunderstanding this subject?
As far as I understand it, the heat death of the universe is a consequence of entropy, not expansion. All processes result in the shifting of some energy to higher entropy. Though the observable universe is an open system, the entire universe is an isolated system, so as more and more energy gets shifted to higher entropy over time the universe will eventually reach a state where effectively no work can be done.