They were militarily useless propaganda troops. I read about an argument where Hitler sneeringly asked why the Frei Hind were always "refitting" without ever having fought.
But what the article demonstrated, as was clear, was that the British Army of India was no longer politically reliable by 1946. India did not have a large, politically powerful white settler population so once the army turned India was lost.
The Indian Army in WWII eventually totaled 2.5 million men, making it obviously a major combatant. But, as you say, it was not a reliable tool after the war for the British to use in repressing the Indian and Pakistani independence movements.