Would be nice to have a Rust compiler as well

You can do DOS target software with Rust... it's pretty limited and the tooling around it isn't nearly complete enough to make anything easy. That said, if you want to make something akin to a Zork text mode game or similar there's that... you can also use ANSI escape codes as another possibility for CP437 text mode interaction.

Only if they invent a 64 bit DOS extender.