The Developer of CoRE, @ady624 has submitted it to ST for approval (and inclusion in the marketplace) but I wouldn't hold your breath.
ST will need to fully review and understand every line of code to ensure it is stable and bug free..... Considering that @ady624 is a far better coder than anyone at ST, that's gonna take a while!
Also, CoRE puts a lot of pressure on the ST servers which are typically running st breaking point most of the time anyway... Release CoRE to the masses and the whole house of cards could come crashing down.
Finally, ST wants to be user friendly for your grandma, and they don't want such complicated apps in the marketplace.... Their support lines won't be able to cope with all the calls / emails that result!!
Manual install is easy enough.... I vote (selfishly) that CoRE should be shared only in the community. Those that don't bother joining the community never know what they are missing and the rest of us get to enjoy faster server speeds