To be fair there's a common way to compile Lua to JVM bytecode so it's likely just a Java front-end, not using the basic interpreter.
Back in the day there was a craze to port Lua, Ruby, Perl, Groovy(!), to run as Java front-ends. Not many got put into production outside of Lua.
However the real point here is that it's now "tell me why I shouldn't use Rust" time.
Moving ABI might be a reasonable objection for a small team but Cloudflare has over a hundred engineers on this so it's not a problem.
They get speed and memory safety in exchange for learning "The Rust Way". Seems like a good engineering tradeoff.
IMO Rust is still for the top 20% of engineers so Java's "solid middle" is still quite safe.