There's a likelihood that no one he would consider reputable or trustworthy has bothered to tell him all his toys and video games are landfill fodder. I wouldn't be surprised if unfunny faggots have written him to tell him. But as you said, Chris would disregard those letters because he doesn't know and trust the writers. If Barb has cut off contact with Chris like it seems has happened, then there really aren't too many people who Chris would believe if they told him "Hey, all your toys, games, comics, and everything else was thrown out because your mother is likely moving out and the house sold to pay off her debts." Although, Babs writing Chris one last letter to say "I threw everything you owned in the trash and I'm moving away." would be one helluva "Fuck you!" from Barb for Chris raping her.
Edit: this is all assuming that his shit was dumpstered. It probably was, but we don't know for certain.