It's an issue with less buttons, quick save is somewhat of a luxury. I use luxury in the most mundane way, but you get my meaning. It's not "necessary" it's just nice to have, so if they have a spare button they might include it, but it won't be a priority. A few games have done it as previously said.
I haven't played on consoles in a few years, but the D-pad tends to be ignored, so maybe they could map it to up on the d-pad, and map quick load to down. Seems like it could work.