Actually I don't expect that to actually happen... air defence layers are good... the more the better.
Otherwise you would say S-500 is perfect and they don't need anything else because it should be able to stop everything from ICBM MIRVs down to cruise missiles and ARMs... except the S-500 will be big and expensive and not likely carried in large enough numbers to be used against everything a ship in combat will come up against in terms of numbers.
It is important to note the Russian Army also uses both TOR and Tunguska... they have a missile regiment for air defence which used to be equipped with OSA, that is in the slow process of being replaced by the far more capable TOR, while in the gun/missile regiment they used to have Shilka and first SA-9 and then the more capable SA-13, but now they have Tunguska, which will no doubt be replaced with something based on the upgraded Pantsir on a tracked chassis for mobility with tracked forces...
They are also introducing Pine... or SOSNA-R to pretty much replace the SA-13s in airborne use, but I also suspect in some areas of lower readiness they will also use them there to replace both ZU-23-2 and SA-13.
(BTW Pine is quite an interesting system... relatively small two stage missiles with high velocity acceleration and low drag second stage missiles with a range of 10km and laser beam riding guidance that is pretty difficult to jam or interfere with... so also rather cheap missiles with all the high tech EO in the launcher so it can be reused over and over again...)
They have mentioned two new versions of Pantsir for naval use, and I suspect one is for upgrades of old vessels and one is for new vessels... the latter being more stealthy I guess, though both would be more stealthy than the original.
This could enable a general shift in Russian armed forces from 4 layer to 3 layer AAD, consisting of Pantsir/Tor merge, Buk and S300/S500.
Actually things are only getting worse... Palma adds Sosna, or Pine, plus a new short range IIR guided missile called 9M100 or Morfei is being developed for the air force(air and space defence force), army and navy, and of course there is the Verba MANPAD...
So in terms of layers for the navy there will be Verba on deck mounts as well as hand held, Sosna-R on Palma mounts, Pantsir, Klintok (TOR), BUK, S-350, S-400, and S-500... so 8 layers, not including aircraft.
For the Army, that would be Verba, Morfei, Pine, TOR, Tunguska, BUK, S-300V4, and S-500, so 8 layers not including aircraft.
Aerospace forces would be Verba, Morfei(though this might be a short range AAM only in this force... but with ground launched models for the other services I will include it here), Pantsir, S-350, S-400, S-500, which is only 6 layers plus of course aircraft layers in greater numbers... you could probably add Nudol and other heavy ABM missiles in this category too however, and if the Pine system is as cheap as it seems they might use it as well... it looks like a rather good cheap low emission system that should also be rather effective.