There's nothing public about anything happening with him. There's certainly no basis for claiming it has anything to do with GrapheneOS. The post above is making a completely baseless claim about GrapheneOS based on someone who said they use it and has no involvement in the project. The claim is based on him last posting on X on August 23rd and previously posting about using GrapheneOS. That doesn't indicate he disappeared and certainly doesn't mean it had anything to do with GrapheneOS in any way. He likely just stopped posting on X.
No it didn't. The post wanted to clear up what happened to Medhurst before trusting GrapheneOS.
But you with your misinterpretations and FUD all over this thread made that question moot. No one should trust GraphenOS based on your comments, because they scream incompetence.