I would doubt that. Most names when they spread out into a new ethnic group are not chosen based on the old spelling, but the old pronounciation. The new spelling tries to capture the new accent etc. Shanti is an Indian name, which all over India (to my knowledge) has the long open a as in English car. Because the standard spelling in the Roman script was Shanti, the name when used for Indians living abroad picked up the pronounciation as in the first part of the word shantytown. I am not aware of an accent which would use aw to represent the same sound. Of course, if the ethnic affiliation of a name is totally forgotten, it behaves like a normal local name: but the can or car to caw development is not extremely common anyway.
I would consider the explanation in the other thread more likely.