I had a Portal 1 gift lying around on one of my alts, it was bought quite early and it wasnt trade restricted. Had way too many unnecessary requests about it and even surpassed my main account's spam, so I just gifted it to a friend. Is it a collector thing? idk, maybe.
I'd highly reccomend hiding Steam gifts from your inventory though if it annoys you.
While they both have the same meaning; he died implies knowledge of the death before, he's dead fits more when you've just figured out that the person in question is dead.