Why do array literals default to object.Object[]?

[Brandon Buck via Digitalmars-d-learn]

I apologize if this has been touched on before, I'm not quite 
sure what to search for and what I did try didn't bring anything 
up.

Okay, so I'm learning D, using the D Tour flow and I went over 
interfaces. Everything is making sense. I key in the example (as 
I like to copy it by hand and then run it locally instead of 
online) and I attempt to make a slight alteration. In the 
previous example, with base classes, the main method begins with:


Any[] anys = [
     new Integer(10),
     new Float(3.1415f)
];

Which makes sense. Integer and Float in that example are both 
inheriting from Any. So when doing the example with interfaces 
where Dog and Cat both inherit from the interface Animal, I first 
tried:

auto animals = [
     new Dog,
     new Cat
];

But got this error:

interfaces.d(51): Error: no property 'multipleNoise' for type 
'object.Object'

Which implies (to me) the auto inferred object.Object, this makes 
sense though. Without basic type inspection they're both classes 
and object.Object is the most reasonable parent of them both. 
Fine. I adjusted my code to better match the class example:

Animal[] animals = [
     new Dog,
     new Cat
];

Surely this works:

interfaces.d(47): Error: cannot implicitly convert expression 
([new Dog, new Cat]) of type Object[] to Animal[]

Different _message_ but same issue. It's inferring Object[]. I've 
told it explicitly that it's an Animal[], and both classes 
inherit from Animal (as the solution and the example on the tour 
page) demonstrate:

Animal dog = new Dog;
Animal cat = new Cat;
Animal[] animals = [dog, cat];

So they can be assigned to Animal fine, but even using them in an 
expression tagged with Animal[] still produces an Object[] value. 
Is this intentional? It feels unintuitive. I understand why auto 
infers Object[] and that make sense, but if I'm using the actual 
type (Animal[]) and can work the long way around to the same type 
(the last example), why can't I do it via direct assignment to 
Animal[]?