Picking Stout Weaver Idols as prophecy and on the next start of the game turns the Stout Weaver idols into Humble Weaver Idols, this is true both for prophecy both bought and in the prophecy “buy” screen. Note this is in offline mode. Video showing this interaction; https://youtu.be/GyBiqH75QVk?feature=shared
I can confirm that this also happens for “Minor Weaver” idol prophecies, after restarting the game they will be loaded as “Humble Weaver” idol prophecies. For my case I am playing in full offline mode.