AWS (which isn't Amazon, really, even if they share resources), used to bake the cost of keeping the lights on practically forever, or at least until the last user churns. The product may not see improvements if it didn't get traction, but you could bank on being able to use it forever.

When they did decide to kill something, like non-VPC EC2, you'd get the notice a literal decade ahead. For this specific example, sunset started end of '13, with the last instance shut off mid '23.

This all started to change a couple of years ago, when they became much more aggressive with doing the Googles and just killing a thing with a few months of a warning. Pity.