> but why not add something new like memory management to learn about?
You can learn that with Nim too. It supports manual memory management like C. The new ARC/ORC GC also works more like modern C++ than a traditional GC.
> its wasm support would integrate with your JS knowledge
Nim can also compile to JS. Or you could compile it first to C and then compile that to wasm, although that's not supported out of the box.