The VW Group already announced next generation Bentleys will get Panamera underpinnings. This won't make for a very cheap sedan however. Especially with that platform possibly being used by Lamborghini as well. Clearly VW wants to get their moneys worth but this may not be a good idea.
VW expected to sell 20,000 Phaetons annually with the first gen model. In four years, only 25,000 were built and slightly over 2,000 were sold in the United States leading to large depreciation. VW may want to evaluate if it is worth doing this again. They have the premium brands for premium priced cars. The fact of the matter is, nobody wants a premium priced Volkswagen seemingly other than the Germans. We will see what happens but this is likely history repeating itself.