Then he would have said a new version of Onyx.
Just read a report about a brand new silent rifle that is entering service, which got me quite excited till I looked at the photo and saw that it was an updated AS suppressed assault rifle in 9x39mm calibre that has been in service since the late 1980s... they don't always differentiate upgraded models with new models...
Or maybe was he talking about ship launched Oniks which isn't really deployed on many ships.
Before they were launching land attack missiles at targets in Syria, the Onyx was the main anti ship missile for the UKSK launchers... its export variants... Yakhont and Brahmos also being deployed overseas too. The main supersonic anti ship model Kalibre took a while to get working right...
There were tests not long ago on last Gorshkov class ship with oniks.
The speeds described suggest upgraded onyx...
MIRV warhead with SLBM fly the same as MIRV with ICBM over 6 km / s.
Speed is determined by distance flown and also radically effected by flight time inside the atmosphere, where most slow down very rapidly.
Think of your hand moving through water... the harder and faster you move your hand the harder the water pushes back... now imagine moving your hand down at high speed through air onto a surface of water.... think of that slap when it hits the water... that is what happens to objects in space entering the atmosphere....
A depressed trajectory flight of an SLBM at a target that is not 6,000km away wont be travelling at the same speed as a normal trajectory launch to targets more than 6,000km away.
The addition of the S-500 to Russian air defence units will likely improve the detection and tracking capabilities and allow more difficult targets to be engaged.
It likely wont be that long before scramjet powered SAMs are developed as it is easier to make a scramjet powered missile travel long distances at high speed than one powered by rocket motor.
The S-400 is not able to capture such targets.
The 4.8km/s target speed limit is for the export model of the S-400 and Turkey has already confirmed in its testing that the system they have exceeds the performances stated...
Only 53T6M can capture some RV from SLBM / SLBM.
The Soviets and Russians had a range of ABM systems in service for quite some time... and they are adding to this capacity all the time.