Just a hunch, but I think the main role of the Hangors will be ASW and AShW.
The PN's main focus right now is A2/AD so as to stop the IN from imposing a blockade or MEZ. It needs boat-hunters that can come in at a good cost and rapid pace, hence the S26 with likely some modifications for Arabian Sea operations. KSEW's 2018 scale model showed some minor differences in top speed and displacement.
But nothing significant IMHO. Yes, the Hangors can carry the Babur 3 SLCMs from their tubes, but nuclear deterrence will not be their main function -- rather, an 'on paper' capability to show we have a triad.
I do think a
strategic deterrent design is on the roadmap, but much farther out. Perhaps -- like AZM -- it could be a design that the NRDI is working on internally (and may reflect the PN's interest in Turkey's submarine projects). But the Hangors will likely be more conservative in scope given the urgency of the PN's sub-surface needs.
@kursed @JamD @SQ8