I understand what you are saying but you've asserted as truth that the author said what you said and in a pretty accusatory tone. If you use 'Imperial India' as

I understand what you are saying but you've asserted as truth that the author said what you said and in a pretty accusatory tone. If you use 'Imperial India' as standalone phrase it does refer to the British rule because it is the most recent and that's what most assume you mean. But when talking about Buddha it is quite a leap to think the author would use such a pointless timeframe so the context alone is enough. Even a paragraph later the emperor Asoka is mentioned explicitly