This article seems more like PR but isn't far from truth. I think, as a community, Jews have probably outdone any one community out there.
In fact, a great many jewish business families in British-India adopted Gujarat, and spoke Gujarati.
Here's another biased take on the topic by a Pakistani journalist:
http://www.livemint.com/Opinion/WaBCEddMLH5DaM0aD5wzbN/Why-I...
And here my answer on Quora on a related question: https://www.quora.com/Why-do-Gujarati-people-make-up-a-large...