Regarding being useful, this is something I strongly identify with. I am not a highly self-interest valuing person, though I see self-interest as itself being a useful value (in the right context). I find that I am more motivated to sign up for cryonics when I look at it as an example to set for others than when I look at it as a way to save my own skin. I am essentially more motivated to support than (directly) to adopt cryonics.

Presumably, a well written CEV optimizer would see our desire to be useful and put us in situations where we can be useful. However, I think it's worth noting that there is quite a bit of wriggle room between the invention of fooming AGI and the development of reversal mechanisms for cryonic suspension. Reversal for cryonic suspension could end up being something that is specifically and painstakingly developed over the course of several decades by humans with normal levels of intelligence.