The social norm compelling a speaker to retract 'it might be raining' upon learning it is not raining is best explained by Gricean updating of conversational commitments, not by the original proposition becoming false.

?Rate how convincing each reason is below to see the overall strength.

No one has weighed in yet. Be the first to share reasons for or against this statement.

Conversational commitments(as used in philosophy of language): The implicit promises or responsibilities a speaker takes on when they say something—like committing to believe what they're saying is true.
Epistemic / Epistemology(as used to understand the broader philosophical debate in this statement): Related to knowledge and what we can know or believe; epistemology is the branch of philosophy that studies how knowledge works.
Grice / Gricean(as used in philosophy of language and communication): Named after philosopher Paul Grice, this approach explains how people communicate by considering what speakers are trying to accomplish beyond just the literal meaning of their words.
Retract(as used to describe why someone stops claiming 'it might be raining'): To take back or withdraw something you said, admitting it was wrong or no longer applies.

Based on where you are in your exploration