After reading the article it is clear to me that Meucci made precursors to the electromagnetic telephone but did not actually invent the modern version as popularized by Bell.
There is no solid evidence for him having created the device or even described how it was created before Bell. He experimented with a bunch of similar things, and filled a patent caveat that described the general concept (i.e. sending voices over a wire using electrical current), but it contained no details as to the actual mechanism. All his descriptions of how he created the device were made years after he claimed to have built it, and after Bell’s version was widely known.
“All-one or none”