Villagers sometimes interrupt a conversation of two villagers when running past them, and will then even sometimes strike up a conversation of their own (!)
Video demonstrating this: https://youtu.be/DDgOyt6jHrk
(probably still processing, video too big for Jira)
There's really no bug here. When they "pushed each other off blocks," you spawn a bunch of villagers in the same place. They're all bound to bump into each other. This is all expected behavior.