[ask] Will we recommand discriminated union compared with general union?

Say we have a following spec, the operation would have a union response, for `Foo | Bar` some emitters may not serialize them easily without a discriminator property so they may fallback to binary data.

In that case does the TypeSpec would more recommand [discriminated union](https://typespec.io/docs/standard-library/discriminated-types#implementing-unions) compared with general union?
```
model Foo {
foz: string;
}

model Bar {
baz: string;
}

op test(): Foo | Bar;
```