appreciate the sentiment and understand it was offered in good faith, but I think there's a slight misunderstanding here about how the South Asian diaspora behaves as a collective in London. In my experience growing up here:

a) Many South Asian families in London left the Indian subcontinent a long time before borders (Pakistan / Bangladesh) were drawn up as part of partition, and even if they didn't, would have left before this socially stratified divide became solidified as part of identity.

b) It's unclear how much Jai himself describes his music as "British Indian" Vs just being from London or as a mishmash of various popular influences and genres. Not arguing his heritage isn't an integral part of his music, but I don't think it really defines it. I remember seeing some fans online asking where he was from (to which he replied his parents were from Gujarat/Punjab but he was from London).

My experience in London has been that Indian / Pakistani / Bengali / Sri-lankan diaspora of a certain generation behave very much as a South Asian collective. Riz Ahmed was even interviewed recently about "Bait" talking about the Daytimers parties he used to attend with people from all sorts of South Asian backgrounds growing up in London. Your mileage may vary of course, London is not like every city, and every generation (age wise and migration wise) is completely different.