Is it normal for a submarine-launched missile to emerge from the water at such a close proximity to a surface ship?
I remember seeing footage of a Russian cruiser firing a similar weapon.
Yes, Russia has some ship launched torpedoes which have an anti ship role such as the ss-n-16, where the actual missile is encased within a torpedo canister and launched from a typical shipboard torpedo tube, and once the torpedo canister enters the water the missile exits the tube and propels itself out of the water into a typical ashm flight profile
But such a weapon is an ASW missile, and the SS-N-16 is launched from a ship's torpedo tubes. 054A features it's torpedo tubes on its flanks rather than its bow, and as far as we know the Chinese navy doesn't have any ship launched torpedo-anti ship missiles...
At the very least I think we can be certain that:
-the missile in the photos (and the video taken from) is being launched from some kind of subsurface platform whether it be a submarine or propelling itself from a torpedo canister like SS-N-16
-because of the above, chances are it almost certainly was not launched from a VLS (why would a VLS launched weapon need to enter the water, and then allow a missile to launch from below the water? Why not just directly launch from the VLS instead into the air. It would be adding an illogical extra step)
-the Chinese navy as far as we know do not have torpedo-anti ship missiles like ss-n-16
-even if the Chinese navy did have such weapons, 054As torpedo tubes are on its flanks and the missile in the pictures are emerging from the water in front of the bow of 054A, meaning the torpedo canister would have had to travel to the bow of the ship first before launching the missile... With all the above, it seems unlikely.
So once we rule out all the impossibles we are left with the improbable, and the least improbable is that the missile we are seeing is a submarine launched cruise missile. Perhaps the 054A in question was close because they were there to observe the test during the exercise.
But at the very least I think we can be fairly certain that this is not an ASW missile launched from 054As VLS.