I don't really see that as the same thing as what the article was pointing out. Those are shibboleths that only an insider would know. You have to get the pronunciation of Cholmondeley or Couch "right" to pass for an insider.

The random misspellings, missing spaces, sloppy grammar, etc in the examples in the article seem different to me. Misspelling "en route" as "enriewu" doesn't show, "look, I know the secret country club spelling for en route". It simply shows that you don't have to care about your mistakes. You write something that approximates what you mean, and you're too important to spend time revising. The mistake could be "enrout" or "n route" or on any other word. But you're not going to be a try-hard who edits and frets over their messages, you're blessing someone with 10 seconds of your attention and they're lucky to receive your correspondence, typos and all.