Using that rule, I don't end up disappointed when a new version finds its way to store shelves shortly after my purchase (it happened with iPods and iPhones in my early years of buying Apple products).
I found out that Apple has a new event lined up to promote new launches on April 20th. However, it is not looking good in regards to AirPods.
The prediction is that the new earphones won't be out until later this year. Therefore, the wait continues.
At this rate, I might end up having to buy an Apple Watch (my other one has broken) and AirPods on the same day! Should be fun...