The distinction between dialects and languages is always rather dodgy and politically loaded (as anyone who uses the words "Chinese Language" soon finds out). One of the better working definitions I've seen is that "a language is a dialect with an army and a navy" -- which would explain why Hindi and Urdu get to be separate languages, but Bhojpuri is sometimes counted as a dialect. Anyhow, I personally am happy to respect both political and practical labelling of things as "language", so if its community of speakers think of something as a separate language then I'll respect that. A dialect may have different inflections and word-usages, but remains mutually comprehensible and is thought of as the same language by its community of speakers. By these definitions, there are roughly 1,600 languages in India[1], and perhaps twice as many dialects.

Anyhow, for Saurashtra, I really did mean "language" and not "dialect". Honestly it's not a typical example of India, but is fun to use for dramatic effect. You know those 500 princely states that existed before unification? 200 of them were in Saurashtra (which is tiny). Politically, it was basically the India of India.

The linguistics seem to reflect that. At one point I recall finding myself in a tiny village somewhere near Dwarka where the residents spoke something completely baffling to me, with not a shred of English or Hindi or Gujarati in the mix. I was completely out of luck communicating with the locals, and had to rely on passing bus drivers for orientation. Later I read a book which said that there were a handful of tiny little Dravidian isolate languages scattered around Saurashtra; I must have stumbled across one of those. The claim of "50 languages" comes from that book, whatever it was. Feels about right, based on personal experience, but I can't really defend the claim beyond that.

(Also I should re-iterate that this was almost 20 years ago, and I very much doubt that there are any places so isolated today.)

1: Per https://en.wikipedia.org/wiki/Languages_of_India: 122 major languages and 1599 minor languages counted in the 2001 census.