Interesting question. My guess would be that, if at all, Minecraft will run unacceptably slowly.
As far as I know, there is no native implementation of a JRE on Sailfish. Here's an old and quite defunct thread about this on the Jolla forum.
Now, I see no reason why it would not be possible to install the standard Linux versions of OpenJDK or even OracleJRE on Sailfish. Initially, this would enable text-only JAVA apps. Graphics in (Linux) OpenJDK/OracleJRE depends on X11, which SailfishOS does not support out-of-the-box. That could however be fixed using XWayland, which can be install