The warning about using for...of states that regenerator-runtime is required:

iterators/generators require regenerator-runtime, which is too heavyweight for this guide to allow them. Separately, loops should be avoided in favor of array iterations.

The explanation creates the impression regenerator-runtime is essential for any code using for...of, which is no longer true, as for...of seems to be fairly widely supported.

I think it could make sense to reword the explanation to state that regenerator may be required and that imperative loops should be avoided.