What do you mean "they can say absolutely nothing about the latter"? That doesn`t make much sense without any examples.
You still have yet to clarify something "out of the scientific realm". Again, just because we cannot test something or lack the technology to do so as of yet does not mean you ascribe it as "supernatural" or "out of the realm" or "mystical". It is completely within reason to say, "we are still working on defining that, understanding that or developing a method that explains X". It is also reasonable to say, "we don`t know yet". But it is utterly nonsensical to posit it as "unknowable" or "spiritual".
I already provided an example: space and time, which e.g. Hawkins agrees with. There are of course many philosophic attempts to explain what space and time are, e.g. by Kant, who came to the conclusion that they are the pure forms of human perception. In any case, these philosophic explanations do not in any way compete with scientific theories concerning only certain scientific aspects of space and time as formulated in the used scientific models.
The point is not what new scientific theories might reveal in the future. It's a matter of principle. Whatever new scientific theories will arise, they are always confined to the same concepts and restrictions, or as Hawkins would put it: a scientist is not concerned with what is real, that is not a scientific topic.
Scientifically observable phenomena which cannot yet be formulated into scientific theories are just that of course. There is absolutely nothing mystical or spiritual about them, I fully agree with that.
