Initial Wayland support was merged in Electron 12.
There is nothing specifically about it in the release notes
but it can be tested with a recent electron version by running:
/path/to/yourElectronApplication --enable-features=UseOzonePlatform --ozone-platform=wayland
If you're using flatpack and your Electron application is Slack you need to create an override to expose the wayland socket as well as setting the GDK_BACKEND env variable to wayland.
The override will be permanently stored in ~/.local/share/flatpak/overrides
flatpak override --user --socket=wayland com.slack.Slack
GDK_BACKEND=wayland flatpak run com.slack.Slack --enable-features=UseOzonePlatform --ozone-platform=wayland