The S600 has been gone for a few years now. The V12 will continue in the Maybach but not for much longer, it’s also due for replacement in a couple of years and I doubt they’ll use the same engine or develop an entirely new one. More likely it’ll be a V8 with the 48-volt system and mild hybrid.
The 65 will be replaced by the S73 with a 4.0 Liter V8 and about 800 hp