Sure, but it's just idle speculation, One might equally write, the dates on the IMDB page may be based upon Jim Tucker's research. One's as fair as the other, but neither helps us to reach clarity over what actually occurred.
IMDB is similar to how a wiki works. You can register as a "contributor" and create actor pages or contribute to existing one. I don't have such an account on IMDB and there is no public history of the creation/edit dates like on Wikipedia. Maybe the data is available to contributors?
@Ian Gordon being quite a cinephile, do you by chance have an account on IMDB? If so could you investigate?
ETA: I've logged in using a facebook account and I was able to access the "Contributor" section but there is no history or timestamps regarding the creation of the page and the edits.
I've shot an email to Dr.Tucker. If he's not too busy maybe I'll get a reply. We'll see...