A contribution receives no answers and the author thinks he is being ignored. I also propose to observe the context: time, number of messages, clarity of the question and habits of the group.
In the hypothetical example, a later summary gets a response that the first message had not received. This does not prove that every silence is harmless.
It allows, however, to verify an explanation before attributing intentions. If the exclusion is repeated and concrete, it deserves a conversation distinct from the analysis of the individual access.