https://arstechnica.com/gadgets/2024/06/macos-15-sequoia-still-supports-intel-macs-but-cuts-the-2018-macbook-air/

Most owners of aging Intel Macs got a bit of a reprieve today when Apple announced macOS 15 Sequoia—this new macOS release will run on the vast majority of the hardware that can currently run macOS 14 Sonoma. Intel Macs released between December of 2017 and 2020 are mostly eligible for the new update, though newer models with Apple Silicon chips will be needed to support some of the new features.

Apple's full support list for Sequoia is as follows: