A Muslim or Christian or Sikh Indian, Pakistani, etc., would not be targets for caste discrimination lawsuits, under the logic.
Of course, as a legal matter, that's not true; anyone could be accused of caste discrimination if the law passes, whatever their religion, race, or national origin.
Having left law to once again be a software engineer, I almost never find myself curious about the development of caselaw, but I think I'd follow that case lol
Hinduism codified and forms the basis for the caste system but every other religion evolved later or was forced upon people who already had caste.
There are definitely things like social stratification based on wealth or ethnic group, and you can see things which, I suspect, are remnants of things adjacent to the caste system, such as Jatis, in the form of things like the Memon community.
Granted, even though I am talking about a range of ethnic groups, I'm still talking about north-west Indian ethnic groups: Gujratis, Panjabis, UP/Delhi people, and Pashtuns. Thus, maybe what you're saying holds true in other parts of the subcontinent--or perhaps just in very rural areas (?)
I replied to "that only indians can be convicted of" but as you point out AND THAT I POINTED OUT it's about Hindus, not Indians. There are big populations of Hindus in Pakistan, Bangladesh, and Nepal.
Basically you just replied "not really; exactly what you wrote".
https://www.bbc.com/news/world-asia-34615972
Japan has generally moved on with heavy government crackdown.