Speaking to a GAL duty manager, Air India are looking at lgw. Huge population in Crawley, makes sense I guess.
Even if
all of Crawley consisted of the so-called "Indian diaspora", it wouldn't be anything like enough to justify a route. It would have to cover a much wider area.
No, it's probably more to do with the fact that AI sold some of its LHR slots and now can't afford to buy them back.