Closed-source editor built on a closed-source framework, telemetry built-in with no documented opt-out, hardcoded language servers, macOS only.
The moment that you open Zed for the first time, you see a welcome screen that offers telemetry opt-out. The editor will be open-source and cross-platform, but it takes time to build things.
EDIT: I just don’t trust promises for things to be open source. Notch said Minecraft would be open source, and look where that went. A promise let’s you skip out on releasing the code if it turns out to be a convenient or profitable options.