I believe this could well be the future at least for supercomputers; finding a way of combining spintronics with superconductors to get the best of both worlds.
Is this development for quantum computers or traditional? I think if trad, the one thing it would do would be to reduce power consumption and that only in the parts using this technique. For instance if the CPU's were spin, that would help but the perifery circuits would still be trad cmos and such, even if like the latest from IBM, they have reduced the size of individual transistors to the 3 Nanometer region, meaning 3 or 4 factor size reduction and increase in speed, probably not 4 times faster but some faster. The big deal of spin is no flow of actual electrons so a LOT less power consumed but only from that which has been converted to spin. Of course that will not take place this year or probably even next year, my guess is 5 years before real circuits are built. It is one thing for a few circuits out of the lab but another thing entirely for a real CPU or memory chip or I/O to come out of a commercial chip plant. The questions there would be, do these chips have to run at 5 degrees kelvin or can they run at room temp? Can they be processed by normal semiconductor technology or is something completely new required to be able to commercialize these parts?
There is a lot of work going on in this direction, not only this bunch, so there will be major efforts to commercialize but it will take years if not decades.
As far as I am aware, nobody is theorizing that these spintronics with superconductors can readily be integrated into a quantum computer, which is quite a different and unrelated concept.
If the chips have to be cooled to just a few Kelvin then they obviously would never be practical for personal computers and small computers and would have their application heavily restricted to only very large supercomputers where the cooling costs can be kept much more reasonable and would be such that there would be an overall energy saving DESPITE those high cooling costs. But even if that is the case, that would still be a big and exciting advance.
But, with spintronics at least WITHOUT superconductors involved, it certainly must be possible to design it to work at room temperature thus spintronics, at least without superconductors if not with them, is definitely the future for nearly all small computers and personal computers.
One has to also keep remembering that quantum computers are only suitable for a VERY LIMITED range of applications, the most notable I think is for computer simulating quantum systems, and especially of life-chemistry, but for most tasks a traditional computer works faster and better.
Thus, and completely contrary to some suggestions I have heard of, small computers such as your own PC will never be designed to have a quantum computer processor as its main processing element because a quantum computer processor wouldn't actually help your PC run faster for at least 99.9% of the tasks it does but rather would actually slow it down!
I think eventually when quantum computers are fully developed they will be integrated into modern supercomputers to answer real world questions like cancer cures and the like. I see them linking up together and becoming stronger than either alone.