When is English not English?

While searching for some references to link to the previous post about English as a lingua franca of Switzerland, I ran across a related article that was thought-provoking. Although English has become a lingua franca around the world, there no longer seems to be a direct cultural connection back to England, where the language originated and gets its name. Here is an essay that expands on this notion and English-language education policy from the perspective of a European.

Anthropologically speaking, a language is one of the primary reflections of a society's culture. However, when a language becomes the lingua franca of the world, in order to reflect the variety of speakers' cultures, the language changes. What happens when English is used by Asians (e.g., Korean, and Japanese) as their lingua franca? Certainly, some lack of differentiation of r's and l's is acceptable because 'they' understand each other. In other words, today where communication commonly breaks down is between native and non-native speakers when conversing, not writing.

Indeed, I have often noticed, as mentioned in the linked article, that non-native speakers can understand each other's English better than a native speaker can. For example, when I teach low level students at my school, sometimes a Swiss student can understand what a Korean student has said better than I can. It is always a bit eye-opening for me since it's my daily job to understand non-native speakers, and I've had a lot of practice listening to many Englishes. Usually misunderstanding has to do with the common misinterpretations of where the stress lies in a word or how non-native speakers have learned to pronounce a word that is spelled a certain way.

Should we have a broader range of accepted/acceptable pronunciations of words? This goes back to the question of whether there is or should be a 'standard', especially for spoken English. Can the lingua franca English technically still be considered English? I wonder what you think.