Is there any shared lineage between this and Whalesong, a previous Racket->JS compiler?

Of course both projects have the same maintainer if I recall, Jens Axel Søgaard is a rockstar :)

Jens Axel Søgaard is cool and involved in many things. We collaborated on SICP support.

Original developer of Whalesong was Danny Yoo. https://www.hashcollision.org/whalesong/

There was also this: https://docs.racket-lang.org/racketscript/

Dave Herman worked on various JS-related libraries for Racket (or PLT Scheme) before he was involved with Rust.

No, there is nothing in common with Whalesong.

Whalesong used the built-in bytecode compiler and compiled the bytecode to JavaScript. Reusing the bytecode compiler is in principle a good idea - but each time the bytecodes are changed, Whalesong needs to be updated.

And after the move to Chez Scheme as backend, the bytecode compiler is no longer a part of the main compilation path.