Hah, really? If you enter recovery mode and install an OS via network it installs the OS the device originally shipped with, right?
On an Intel-based Mac:
- If you used Option-Command-R to start up from Internet Recovery, you might get the latest macOS that is compatible with your Mac.
- If you used Shift-Option-Command-R to start up from Internet Recovery, you might get the macOS that came with your Mac, or the closest version still available.
On an Intel-based Mac:
- If you used Option-Command-R to start up from Internet Recovery, you might get the latest macOS that is compatible with your Mac.
- If you used Shift-Option-Command-R to start up from Internet Recovery, you might get the macOS that came with your Mac, or the closest version still available.
https://support.apple.com/en-us/102655