According to this page: https://ai.google.dev/gemini-api/docs/models#preview Preview models are given at least two weeks notice between deprecation and shutdown. However, the deprecation of Gemini 3 Pro Preview was announced on February 26: https://ai.google.dev/gemini-api/docs/changelog, which is less than two weeks before the planned March 9 shutdown date. (two weeks later would be the 12th).