There is no decentralized algorithm for timelock encryption. No such scheme exists. Distributed is the best you're going to get without a radical breakthrough, and that's exactly what TFA is.
Even with some corrupted nodes, the message would still be secret, the only issue would be if the last nodes are corrupted : your message would be distributed too soon. But with enough layers and enough nodes to go through, you could mitigate this risk.
The network could even detect corrupted nodes if other nodes received the message too soon.
However, you could mitigate this by calculating hundreds of routes.
But yes, you are right, that was just an interesting thought experiment before going to bed, I wasn't trying to revolutionize timelock encryption ;)