Not a 767 replacement
Don't forget that these aircraft are to replace existing A320's. The replacement for the 763 is of course the 789.
It should close the gap nicely between the A320 at around 170 seats and the 789 at circa 300.
Seems ideal to me. 789 on the long haul flights were the 763 is barely palatable currently, or high density short haul when loads dictate. A320/21 for all other short haul.