Not necessarily. R doesn't have other implementations, for example, and Julia still has some way to go before it catches up with R popularity-wise. Or consider Python - it does have several implementations, but the vast majority of the ecosystem is centered around one, and many libraries don't work on the others in practice (especially anything written in other languages using the extensibility API).
Well, technically it can be argued that R is itself an implementation (of the language S). It's just that the alternative implementation has become defacto and replaced the original...
