Launcher was merged with GameSync
https://github.com/EpicGames/UnrealEngine/commit/da6a8f045eadf2680a23c408c16cec99b180f5d3
" UGS: Merge UnrealGameSync and UnrealGameSyncLauncher.
Having one application for launching and running UGS makes for simpler and easier deployment, and allows easier code sharing between the tools. By default, debug builds of UGS will launch directly into the UI, while release builds will do the standard upgrade check. Passing -noupgradecheck will force it to launch directly, and passing -settings will open the update configuration UI."