It looks like Boeing is making more of a 767 replacement. (Decision supposedly coming this year if the proposed EIS date of 2025 is to be honored).
The "797" would be a twin aisle widebody above floor level but only enough space for one cargo container so essentially a narrow body below floor level.
200-280 seats beyond 5000NM
The 321LR NEO is supposedly able to do about 80% of current 757 routes so it seems as if this is the closest 757 we would get. (Airbus is also supposedly considering making a 322)
Interesting times ahead.