Just as one would hope:
```./a.scala:9: error: type arguments [Int] do not conform to class C's type parameter bounds [T <: SomeClass]
  new C[Int]
      ^
one error found```

The restrictions are identical; the difference is in whether said restrictions are to be ignored at the point when they are most needed.

I can see that it would be nice if the error message said something more like

```...do not conform to class C's (inferred from def x: MyClass[T]) type parameter bounds [T <: SomeClass]```