I think Random facts are okay but when you explain in some detail, how a character dies that's not a random fact it is plainly a plot spoiler.

I think there are ways to gives some random trivia without giving away the particular plot details.

For instance the following are facts that don't give away plot details of how character "X" died:
"X was the first Decepticon in fiction to be killed by a 'Heroic' Autobot"
"Five Decepticons, (X,X,X,X,X) have died as a result of being betrayed by a fellow Decepticon"
"Character X was killed because Hasbro had lost the rights to sell the toy and didn't want it promoted in the show anymore"

However I think there's a lot more TF facts out that people don't know that don't give away character deaths or how the story ends.