tbf, there is legitimately nothing new about long range underwater explosive drones or landing probes on extraterrestrial bodies.
There is a first time for these things, and neither of these is a first. Assuming you believe Russia’s claims anyway, which actually probably isn’t a very good idea. But regardless, they did already claim to have one.
Now, that’s not to say that iterating doesn’t steadily improve methodology. I’m sure India’s modern probe is better than anything we’ve put up there so far. But it’s still not a first.
Point being, can’t we just call a torpedo a torpedo, if torpedos already exist?