Solving the aging problem will be nearly impossible. Remember that your cells do not actually have good enough tools to solve it on their own. That's a huge fundamental problem. Here's how you exist from a lineage that's billions of years old. You are composed of lots of cells that are constantly degrading. You can generally make it to reproductive age, but not with certainty. So then you try to make a baby. The vast majority of sperm are abnormal, approximately 96%. The bad ones mostly get weeded out trying to make the long journey to the egg. After fertilization, up to 75% of zygotes fail to result in a live birth. So this filtering during reproduction is one of the main mechanisms for how our cells have survived for billions of years. Our somatic cells truly lack the ability to ever get restored to full health, no matter how much we might try to help them. For example, with the OSK approach, our built-in toolkit will result in success in less than 30% of the cells or even lower. What do you do with all the rest? Kill off some of the worst senescent ones? OK, but you're quickly getting into chaotic territory. For example, you would still need to somehow replace the mitochondria -- not just add new ones, but also remove the old ones. That won't happen. Sure, we might make some sporadic progress, but I strongly suspect that it will be very gradual and very minor. There is no anti-aging revolution coming and there's no such thing as longevity escape velocity. The problem is fundamentally too hard. By the time of the Great Upload Event, my guess is that we will only have added about 10 or 15 years to maximum life span.
However, the replacement approach should work. That's where you just grow new organs and body parts from your own stem cells. That will work because we can do our own filtering for good cells in the lab. But that won't be easy. For example, you'll need good mitochondria, so that would involve a lot of filtering or some actual alterations to the stem cell. We'll also clearly need fantastically complex microrobotics, but it does seem basically doable. That's not what most people think of for anti-aging, though, and it's a long way off, probably 70 plus years to fully mature.
Until then, people will just keep dying of old age, so brain preservation will surge in popularity long before aging is solved.