There will be no more immune monsters except for EXTREMELY rare cases. Bosses will be using high life / all damage reduced for their tankiness now. It feels bad to be crippled just because of your element you're playing. Conviction / similar auras / curses will still lower resistances, but will cap at -25%. It will be removed from all items, including the ones you mentioned, and replaced with something else. It may still show up on an item in again, EXTREMELY rare cases, but don't expect to see it much.