It will get Golden Gate. Not sure what will happen after 2027. However, Apple will still provide security updates for older OS even after a new one has come out.
So you can expect ~2-4 more years of updates for an M1. Even after no updates, you can probably still use it longer.
This is entirely inaccurate. M1 is Apple Silicon and will be fully supported in Golden Gate (macOS 27). Support in macOS 28 is also practically a given.
