The day OpenAI named in its March announcement arrives, and the Sora app and web experience go dark. The API continues for one more development cycle and is scheduled to end September 24. The actual sunset clarifies something the launch hype obscured: even frontier AI products with cultural moments of their own can disappear inside two years. Every creator who built a workflow around a closed model now has a fresh case study for why portability — and open-source backups — matter.