This is my main objection to the concept of “multiverse”. You cannot have more than one of “everything that exists”. By definition everything is everything.
I think that whatever happens to the state of matter in our “universe”, whether the galaxies go away or all the stars burn out, there will always be something that exists.
What form that takes, I could not say. Perhaps if someone in billions of years was to look out into space, they would not see stars and planets as we know them, who knows. Perhaps no living entities will be there to do so.
But, that does not mean that there will be nothing that exists. Something will exist. There is no alternative to existence, to something existing in some form.
So, in that sense, the universe is eternal, as whatever exists, exists. So, there is always some “totality of existence”.
Are waves in water an example of particle-wave duality?
No. But, perhaps this is a good chance to explain the issue of particle-wave duality.
When you say “there is a water” wave, what are you referring to? Which physically existent entities are you talking about?
For that matter, what are waves?
We will start by answering the latter question.
A wave is a relational concept. It refers to the cyclical motion of something or some other cyclical change in one of its other properties. In other words, it is simply an abstraction which identifies certain patterns in somethings behavior.
But, does a wave physically exist? No. It is an abstraction, nothing more.

Ah, what about water waves, they exist, right? The water molecules certainly do. They are arranged in a certain pattern and we call that pattern a “wave”. But, the wave is an abstraction. What exists is the water.
It is similar if you look at things on a quantum scale. If you observe a wave, then you are observing something which is waving.
Ah, you say, but we observe that a photon (or an electron or what have you) actually is a wave. Just look at the double-slit experiment.
But, that is not the case. If you observe a wave, then you observe something waving. A wave is not a form of matter, nor do entities themselves physically exist in the form of waves. As waves are abstractions, not a form of existence.
Whenever you see a wave, you are seeing something waving. That is, something exhibiting some kind of wave behavior.
What does this have to do with the question? Well, something. Nothing is an example of particle-wave duality. As nothing that physically exists is a wave, only something that waves, then nothing can be a particle and a wave at the same time.
How deep is Deepak Chopra‘s understanding of quantum physics?
I would say that it is virtually non-existent. He does not really understand much of what quantum physics actually says.
He likes repeating phrases such as “quantum-leap” or “discontinuity” without having very much understanding of what such concepts mean in quantum physics.
Now, granted, those ideas can be very difficult for one to get their head around. So, if it was just that he did not use them very precisely, I think we could cut him some slack.
But, he uses them in a very sloppy, ignorant fashion that it is clear that he has made very little effort to understand what the ideas are supposed to mean.
This is complicated by the fact that he almost never corrects his mistakes, no matter how many times he is corrected.
But, what should we expect? Clearly, he is not an honest person. He has no interest in reality nor understanding ideas. He is more interested in using confusing terms in order to make himself seem smart so that he can fleece people out of money.

Why does he use so much quantum quackery? Because there is a lot of really difficult to grasp stuff in this part of physics.
But, more than that. There is a lot of nonsense. Such as particle-wave duality, the idea of things being in indeterminate states, quantum leaps and the like.
I know this is a very unpopular opinion in most circles: But any rational person should reject many of the interpretations offered in much of mainstream quantum physics.
Why? Because they are nonsense. And they help to undermine the credibility of science.
How is that? Well, if I am right and quantum physics has a lot of nonsense in it, then it is easy for people like Chopra to use it to try to make their own nonsense sound credible.
They are in effect saying:
“Look, science says my mystical mumbo-jumbo is true!”
And how can that be good for science? It clearly is not.
But, the bigger issue is that quantum physics is so mystical in the first place. The fact that Chopra is so prone to using it to try to bolster his nonsense is no coincidence.