finding him before a predator got him, or he died of old age.
You mean like what should've happened a long time ago, making the events in #48 completely impossible? LOL If Rats live for about 3 years, the war lasted 3 years, and David came into the picture
almost a year into the war. That would mean that by the time 48 happened, he should be really old and like on his Rat death bed. and if age didnt kill him then im pretty sure a seagull or some bird of prey, that just happened to pass over the island he was on, would've. LOL so in truth, David shoulda been dead before he met up with Rachel again. As for telling his parents, I personally think it'd be insulting to not tell them the truth. He was their child and they have the right to know. However I would've lied because:
1. I hate being the bearer of bad news
2. They'd probably start blaming me and the other Animorphs for how he turned out(they woulda done that even if I told them he were dead though) which might escalate into them trying to go to court
3. Would you really have the heart to tell them parents that their son was an angry psychopath who you had to trap as a rat for the rest of his life and that he was probably digested by Tobias'(LOL @ funny fanfic) by now