This was a great read. However, before you jump to predigested interpretations, you may consider that matter/energy is equivalent with information and neither energy nor information can be destroyed. Those are demonstrable facts.

https://senderspike.medium.com/absolute-equivalence-b4584dc2e290

So when you ask, "Where are they? Do they still exist in some sort of meaningful way?" the answer is straightforward -- all around you. As effects of all their actions, thoughts, etc. As your memories and so on. Furthermore, if you are curious whether, "Will I see them again, share good times, play a little golf, talk over the lives we had and still have? How, where, why?" I'm afraid that beyond dreams or states of heightened awareness (which "merely" allow for "anomalous" access to all information throughout the universe), no. Though, as far as I'm concerned, that's plenty.