No, not those prequels. Have you ever played a game with background lore which was as good as or better than the game's main story, and it made you want to see a prequel? If so, share yours here.
A big one for me would be Final Fantasy X. I'd love to see S-E make a prequel set 1,000+ years before FFX, during the machina war between Zanarkand and Bevelle. Maybe Shuyin and Lenne could be the main characters, and we'd finally get to see Yu Yevon when he was a human, and the game could end with him performing the initial summoning of Sin. I think it would be fascinating to see Spira before Sin destroyed it. They could also explain the origins of the Al Bhed, which I'm curious about.
A prequel to Horizon: Zero Dawn would also be great. I'd love to see a third-person shooter where you have to fight the Faro machine swarm to buy time for the Zero Dawn project to be completed.