Boeing is not stupid. Maybe by the end of the year, they'll release plans for either a 797 or a 737-2100/-2200/-2300 (new landing gear and engine). They are doing their calculations now, I'm sure. If they come out with a 797, Boeing will get more orders than the A320NEO. Boeing just has to calculate which generates more profit, spending lots of money for 797 development or less for a 737-2100.

Note: I made up the 737-2100 name. It could be the -1000 but that sounds basic, like the -100, and means that a -1300 would be close to being used.