Scenario 1: big change occurs, tell the bees. Bees continue to do their thing. You gain no information because nothing changes.
Scenario 2: big change occurs, don't tell the bees. Bees continue to do their thing. You gain no information because nothing changes.
Scenario 3/4: no change occurs in your life, nothing to tell the bees, so it doesn't matter what you do/don't tell them. Bees continue to do their thing. You gain no information because nothing changes.
Scenario 5/6: no change occurs in your life, nothing to tell the bees, so it doesn't matter what you do/don't tell them. Bees pack up and go. Welp, can't have been your fault - they did it all on their own!
Scenario 7: big change occurs, you tell the bees. Bees pack up and go. But when? Right away? How does one attribute the bees leaving to YOUR actions specifically - it could have been the weather! And why would you? You did everything right & told them! There must be some other cause. You're also a little ashamed about them leaving, so you hide the information from your tribe. Also, the people you give the information to refuse to believe information that disproves the "obvious" theory that "everyone knows", that you must tell the bees.
Scenario 8: big change occurs, you don't tell the bees. Regardless whether the bees pack up and go, you're feeling a little guilty for not keeping up your tradition (which you know your tribe has come to expect of you), so you're primed to associate any change in bee behavior with your own change in behavior. The bees could even take several months to pack up and go - thus giving these scenarios a higher likelihood of occurring. You still blame yourself, and you tell your sad tale far and wide.
Your reaction to the Scenarios where the bees pack up and go are the only times the you gain information. That makes them the times you're most likely to talk about to your tribe. "I did stuff and nothing happened" doesn't make for much of a story and isn't useful to others so they won't remember it.
And because this is all about storytelling and trying to survive, your tribe will pass on any story believed to help them survive. The fact this is happening for every beekeeper everywhere and they can talk to each other amplifies any individually held superstition, which helps to reinforce the superstition and pass it down through the ages.