When we can upload our brains to the cloud, and you can do something with them like interacting or running the brain, then we'll all be effectively immortal. That's a pretty big deal. See the book altered carbon.
They wouldn't be us. We will still die when our bodies fail. But maybe there will be some AI tricking our friends and family into thinking we're still there.
You are making a claim that is theological, religious, and scientific. Yes, our form of life on earth ends when our bodies die today. But what is the essence of us, no one really knows. Various people claim it's locked into your body, or you have some kind of soul that depends on your body. Or your brain is just running a program and the information and mechanism dies when your body dies. I lean toward the last category, but no one knows.
The body is constantly changing. We already know about physical and chemical abnormalities in the way your body works affects your "person" and we can sometimes address them with surgery or drugs. The physical body's limits impact the observed brain. If uploading is possible, if there are some examples of working cases, if I don't hurt anyone why not try it?
The Ship of Theseus is a weird one too. If you take a car apart and replace it piece by piece and replace the whole car you kind of have the same car. But what if you kept all the old pieces and put them back together? Which one is the original car? It is a interesting thought sub experiment that plays on the 'Ship of Theseus'. You could end up with the same issue here. If I make a perfect copy of myself, who is the 'real' me? There is an obvious 'older' me but the other one is just as capable as I am.
If you keep the original bioware fully operational, it's more like an incremental fork running on an emulator. You can start having conversations with your approximated self.
You'll have tiered processing, just like today. You can slum it out with limited simulation capabilities, or if you have a job you can afford the premium processor hours.
I bet soon after the first few people are made immortal this way, one of them will hack the banks, or the stock market, or countless other organizations.
The show upload on amazon prime is basically this world. If you don't have as much money your instance can pause. You pay more money and have access to nicer things in the afterlife.