That's probably, singlehandedly, the most stupid idea on the forums, or aat lesat in the solid Top 10
It would kill the game. Perma death is popular among fringes of gaming community and does not justify te multi hundred million dollar budget. But, if somebody loves a single autosave, they just may not use manual save.
Also, any fuckup during the autosave (which happens A LOT) would ruin anything from 5 minutes to 200+ palythrough, most probably forcing the player to rage qiutm, uninstall, and proceed with 50k characters hate post on every single game forum.
Still, an option to have "Iron V" mode could work. But I could bet that after 50hs of game any gaming hipster would start a new game with manual save enabled