The Sea Eagle is described as a MPA but it is definitely capable in Anti-submarine warfare. Going away are the days when MAD were really super important. The modern acoustic sensing suites make them redundant. That is why P-8s dont have them either (although Indias P-8I have them at special requests). That said with their advanced Acoustic suits and Maritime AESA radars, the sea sultan and sea eagle are really set up similarly to P-8 and should be quite capable sub hunters.
Do we know whether or not the sea sultans will be able to carry AShM? These carrying air launched Babur/Harba or even naval versions of would be very helpful. They would be even more helpful if they could launch CM-400 or CM-302/YJ-12.