Yes, it is not even close, I agree (based on my limited investigation of Morton, likely a fraction of yours, I fear).

What they do share, however, with many other musicians who gave inaccurate birthdates, is chronological unreliability, obviously.

And what Morton, in his “bad half,” shares with some of said musicians, and others, is an acute “I created Jazz” syndrome. With a “My friends and I actually composed such and such famous song, and we were ripped off” complication.

One might argue, as Morton did, that Handy himself accepted the rather ambiguous “Father of the blues” title, but Handy literally spent decades explaining that the genre he popularized was the “polished” version of a pre-existing form.