We sometimes accept “not totally free” software. Minecraft is neither free nor open source, so that’s a firm “no” for it to be in the catalog. This should not prevent you from installing it with the address of the repo.
I know Minecraft Java Edition is already existed on YunoHost GitHub Repro. But, will it be also great if they add Minecraft Bedrock Edition to YunoHost GitHub Repro?
Just to add a little info about Minetest, there are a few plugins existing in Minetest, and a few of them are to make it as close as possible of Minecraft.
In YunoHost, for now, 2 plugins are available from the web-install directly, one of them is Mineclonia.
So, OK, this is not Minecraft, and there are a lot of differences, but it is quite close, free, and open source.
I know this may not be what you want (if you want Minecraft, this is NOT Minecraft), but from my point of view, it is a really nice alternative.