If you have installed Minecraft Dungeons in a custom directory, there is a chance uninstalling Minecraft Dungeons Launcher and/or the game will remove the entire parent directory and everything in it.
Before uninstalling anything, please ensure the Minecraft Dungeons Launcher atleast uses Bootstrap version 166 or higher. You can check this at Settings > About > Bootstrap.
Restarting the launcher should give you the new version.
I've been reading online that this bug was causing entire disks to be wiped out, which was not necessarily the case. So I'd like to clarify what the bug was about in more detail, and what is the fix we released within around 30 minutes after hearing the first report:
When a player selected a custom "Install Location" in the Dungeons installation dialog, the Dungeons Launcher was taking that location and naively considering that only files written by the Dungeons Launcher would live there. Thus, when uninstalling the Launcher, the uninstall logic would simply delete that "Install Location" folder, to leave no traces of program files created by the Launcher on disk.
We didn't consider that the custom location chosen by players could also have files belonging to other programs in it. And unfortunately, we didn't catch that in tests. So the bug would only impact players who had selected a custom install location for Dungeons where other program files also exist, then tried to uninstall the Dungeons Launcher.
The fix we released soon after hearing about the first report (which is in Bootstrap version 166 and up) is to delete only the folders that the Launcher knows about, under the Dungeons install location.
We are very sorry for the inconvenience this might have caused to players and will surely take this as a learning experience for improving our quality assurance process.
I had the Minecraft Dungeons launcher installed on my SSD with all my games, it wouldn't let me install the game in the same place so I uninstalled the launcher so I could install it on my C drive but it wiped out my entire games SSD!