Mind-boggling, but I love to explore and consider the idea, in my limited abilities.
I think that reality is far more vast, strange and so totally beyond our understanding that there will always be more to learn.

Like All Theories, It's Possible.

There are a lot of interesting possibilities and speculations, and despite all our measuring and best thinky thoughts... we are still not sure which picture (if any) are accurate.

A few thoughts I have along these lines that may or may not be related to how you are thinking of this question:

If there are "universes" adjacent to ours in any fashion, uniting them in any way... even the smallest exchange of information or energy, would unite them... just "detecting" such a universe would mean that it was not in fact some other universe... but indeed, part of our own. If, however, we were unable to detect an "adjacent" universe in any way... a truly seperate universe, then it may as well not exist. Just like god. So... something akin to parallel universes may exist, and if discovered... changes our scale. Our present understanding of the universe becomes a unit of 1 in a new scale measured in universes. Just semantics, I guess.

The other notion that likes to flit about in my mind when considering the notion of multiverses, is the layering of parallel realities. At the cellular level, your body is a whole different world. All kinds of details and denizens we can't see from our lofty heights. The same can be said for our relation to celestial bodies. Imagine the solar system and the milky way as though you were the size of the sun. There are more scales than that, but it's interesting to think of "realities" being layered in this way. As you zoom in, or out, new details and hidden worlds reveal themselves. Perhaps there is no end to the scaling.

Possible but not proven. Similar to the idea that we are living in a simulation.

If you just dabble in quantum mechanics for any time at all you tend to go that way. Some of my favorite quotes come out of the study. I guess Richard Feynman had it right when he said "it's safe to say that nobody understands quantum mechanics."
Hopefully scientist like Michio Kaku, Joe Polchinski and others will make amazing discoveries in my lifetime.

If the Universe has a beginning, maybe it has an end. Maybe after the Universe ends it can begin again... and again. How many ways is it possible for the Universe to play out? Possibly 1, maybe a countable infinity, or maybe 47?

Is that where the alternate news comes from?

The theory of Branes says there are and I believe that that theory is on track.

It's pretty much been proven already. Mathematically, they have to exist for certain physics formulas to work.

I'm gonna go out on a limb here, and say "Who knows?"

My thoughts are pretty mild. I’m more of a day by day dude. But I’m a big Rick and Morty fan! ?

I feel they are more likely than not.
There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.

I like it. I mean, we kind of have that here on earth but different societies.