This is nonsensical. Even if you're right, then most people who don't want cryonics are just mistaken about the probability of success. Being mistaken about something cannot be either suicidal (in the ordinary sense) or selfish, since both of those require conscious decisions.

If you think a bridge is safe, drive over it, and fall through to your death, was your decision to drive over the bridge "selfish"? Of course not. It caused pain and grief for the survivors, but not knowingly.

PS: What's your estimate of the probability of success for being rescued by time travellers if you make sure you die in a closed vault so you can be rescued without changing the past?