“THE MOST IMPORTANT CHANGE IN ENGLISH IN CENTURIES”?

“THE MOST IMPORTANT CHANGE IN ENGLISH IN CENTURIES”? I have posted several times (including here) about the Northern Cities Vowel Shift. Rob Mifsud in this article in Slate says that some 34 million people, from Syracuse to Milwaukee are involved in this shift and that the shift “may be the most important change in English pronunciation in centuries.” I am proud to be part of the 34 million. The Northern Cities Shift is compared to the Great Vowel Shift, which began about 1400 and changed the pronunciation of long vowels. The Northern Cities Shift affects short vowels, which—Mifsud points out—have been pronounced the same way since the year 800.