Initial thoughts:
Since they would be “hunting” for Ben Solo he wouldn’t actually be in it as much as the other characters, so it might have looked like the Rey movie they’ve already worked on and cancelled (twice?)
People liked him as a villain, and people generally didn’t like the last minute romance, so it’s hard to say that the popularity of the character would be there.
I missed this supposed title somehow. Would it be like The Search for Spock LOL