He sounds like he is in love with another person in his more recent years, that is why he is saving a place in the future for her in case it works out again.
Its not Joe from his words, it sounds like he doesn’t want anything to do with her romantically, their personalities are best fit as friends. Most guys don’t draw lines like that unless they really have no more feelings for you, otherwise they would usually just say “Leave up to fate. Undecided.”
Guys will reminisce about the most beautiful girl they have come across and have had relationships with, sorry to say but Wallace met too many women after Joe that she’s prob at the bottom of them since it was a decade ago, so he has had so many new experiences that overshadowed a reallly old one.