Your theory is somewhat flawed. The expats and the age 60 plus pilots in India are mostly experienced commanders which India needs at present. Getting rid of the expats prematurely or reducing the age to 60 does not help, not at present.
The 5000 CPL holders have less than 500 hrs TT with zero experience.
Until the present F/O's get their command CPL holders have to wait.
As more F/O's get command then the phase out makes sense.
If the 600 odd expats left, who will fill those slots?