10 years from now IRC will finally allow you to upload images and documents in the discussion while the Slack competitor will have figured the perfect blending between instant chat, asynchronous long-form communication and concurrent editing for documenting the decisions that were taken. It's easy to keep a protocol alive when the protocol does almost nothing.
We'll talk about it 10 years from now when Slack is gonna be "old cruft" while IRC still gonna be there rocking.