The NSA will have to satisfy itself with being the most powerful intelligence agency in the world. President Obama, rushing through some last-minute presidential business before handing over the title to an aspiring plutocrat, has split up the nation's cyberware command. This siloing prevents Cybercom from being run by the same military officer who oversees the NSA.

“While the dual-hat arrangement was once appropriate in order to enable a fledgling Cybercom to leverage NSA’s advanced capabilities and expertise, Cybercom has since matured” to the point where it needs its own leader, Obama said in a statement accompanying his signing of the 2017 defense authorization bill.
Basically, no one man should have all this power. This scales back the NSA's offensive involvement, leaving it to play defense for the US government -- a limitation it's never been happy with.
The offensive end of the nation's cyberwarfare will now have its own leader, which points towards an increase in offensive efforts, rather than tighter handling of the reins.

Sticking the NSA with defense doesn't make it happy, considering the wealth of offensive weapons it has at its disposal. But having a new singular focus may help it refine its pitch for a cut of some unfiltered domestic data. The NSA would rather be in on the ground floor of the information sharing forced on private companies by the recent passage of cybersecurity legislation. If it can defend the government's most sensitive networks, surely it can be trusted handling the civilian side as well?
Obama's approval of the defense spending bill may be putting different hats on different individuals, but his letter also notes that the more things change, the more things aren't really going to change for the foreseeable future.

“The two organizations should have separate leaders who are able to devote themselves to each organization’s respective mission and responsibilities, but should continue to leverage the shared capabilities and synergies developed under the dual-hat arrangement,” Obama wrote.
So, there will be two different figureheads leading two different Cybercommand wings… but working together in the same building… using the same NSA-developed tools… during a "phased transition" with no clear endpoint.