I think India do not have much choice. They r impossible to buy Chinese arms. Russia arms are getting more and more obsolete. This left India with US arms of choice only.And the Turks will really appreciate that, it will do wonders for USA-Turkey relations!
I too think that USA will make an exception for India.. but, it will diminish USA's ability to pursue that policy if they do. So, will USA have to drop the CAATSA .. has to ..