What is this, Jeopardy? To some pastry chefs, a mixture of pastry cream and whipped cream is a quick-and-dirty Bavarian cream. Others simply call it a light pastry cream.
A Bavarian cream, you will recall, is a yolk-only egg custard stiffened with gelatin, into which very soft whipped cream is folded. Bavarian creams may be flavored with nuts, coffee, chocolate, fruits, or liqueurs. Bavarian creams are often formed in molds and can be the filling for charlottes.
A pastry cream is an egg custard made with whole eggs, and stiffened with cornstarch or flour. Because it is stable and relatively stiff, it is used to flavor pastries instead of whipped cream, which would just make the pastry soggy. Pastry creams can also be flavored with fruits, liqueurs, chocolate, coffee, etc.
The faux Bavarian cream you refer to would be less light and also less rich than a real Bavarian cream. But because pastry cream is often available in the refrigerator in commercial kitchens, using it to make an approximate Bavarian cream can save a lot of time.