Greetings Michael:
Beyond what I've attempted to explain in two previous posts, I have yet to uncover any additional information that would prompt me to suggest anything more than, "Mother Nature can be unpredictable in her ways" and that we often witness negligible acorn crops following a bumper crop acorn season.
However, if this phenomenon happens next year, the year after, and the year after that, then I would contend, as you currently do, that further investigation would be necessary.