Without relying on prophecies etc like the PT did - I wonder if Leia is looking for Luke because she is aware of some shadowy evil at large that only the ‘DYAT OF THE FORCE’ can defeat - so she might assume its her and Luke - but then it turns out to be Ben and Rey? No idea how you’d introduce that.
I always felt it was a missed opportunity in the PT to not have the Jedi speculate that the Chosen One wasn’t someone else (like Dooku or Mace Windu) - then have a twist that it was the overlooked Anakin.