If you can shadow previous bindings then that would also cause no problem for repl re-usage, unless the shadowing syntax is different to the binding syntax.
Either way, unrelated to the point in the article about the advantage of immutable values for repl, not immutable bindings.
I would certainly agree that truly immutable bindings would be at best quite a stumbling block for repls, but so far no one was advocating for them as a good repl feature.