Not sure who Dave is....
Delphi doesn't know that the type of the thing to the right of the equality operator is an array, it thinks it is a set. That's why you get the error. You might not like this, but this is just how it is right now.
From the language perspective, there is clearly some magic disambiguation applied in the case of the assignment operator that isn't applied elsewhere. As Remy says, all you can do is to open a ticket. Shooting the messenger isn't going to get you anywhere.
But even if the code did compile, what would you want it to do? For dynamic arrays, like other reference types, the equality operator = means reference equality. But I suspect that you would want value equality. So even if this code ever compiled, I don't think it would do what you want to do. In which case you will need to implement a method or function to perform value equality testing, and so the topic becomes somewhat moot.