Interesting analysis regarding Indigo.
STN have been listing for some time the Sub Continent as a likely destination.
Hopefully something may come from this latest interest. Indigo did have LGW slots in the past but it is interesting they may now regard LGW/LHR covered to an extent with their THY code share.
It appears the latest A321XLR model/s are probably going to help opening STN up to new operators & destinations.
Whether detrimental or not to the Indigo prospect is the news elsewhere that Jet Airways are at least for this evening cancelling all international services inc LHR due to only having just over a dozen a/c available now & also defaulting on Indian licensing obligations for International services by operating less than a stipulated 20 a/c overall.