About a bit ago the Base OS pack has been updated again to a version 6.0.7303.0
It is not advised to upgrade your SCOM packs to this version yet, because it has some bugs in it.
Kevin Holman writes about it here:
So would hold off until a newer version comes out (hopefully soon) and please check it in your test environment before you let it hit production. A lot of other packs have references to Base-OS packs so it is hard to remove it when something goes wrong.