Microsoft Chairman Bill Gates answers questions during an interview Jan. 21, 2014, in New York. (Don Emmert/AFP/Getty Images)

On top of Microsoft's big announcement Tuesday naming Satya Nadella as its CEO, the company has confirmed another circulating rumor: Bill Gates is coming back.

The Microsoft co-founder is set to step down as chairman of the board and, according to the company, intends to take a more active role "shaping technology and product direction."

This latest move may bolster confidence in investors who believe Nadella lacks the experience to oversee the company's work on consumer devices. Critics say Nadella, who previously led Microsoft's cloud computing division, doesn't know enough about retail. Making Gates a close adviser on products would help shore up that deficit, or so the theory goes. Nadella reportedly asked for Gates's help himself.

But whether Gates is the right person to fill that gap is a different question. There are a number of reasons why Nadella might want to avoid leaning on the former CEO. Microsoft isn't the same company that it was when Gates stepped down as CEO in 2008; it's since been through a major reorganization under Steve Ballmer that puts more emphasis on its "devices and services" approach. Gates may be ill-prepared to return after being largely absent from the tech industry for six years; most of his attention has been devoted to his important philanthropic work on global health, and Gates last month said he'd work on his foundation full-time for the rest of his life.

Meanwhile, Gates's close association with the personal computer is, in some ways, exactly the opposite of what Microsoft needs, which is to shift away from that slumping market. And then there's the matter of Gates's personal influence on the company, which may have waned since 2008 but at the time was so strong that one analyst said it was god-like in its power to stifle creativity.

"The problem with Gates taking on that role," said Michael Silver, a Gartner analyst, "is suspicions that he’s played a larger role in the company over the last few years than people think, and that he bears a lot of responsibility for the trouble Microsoft is in today."

Gates has had his own visionary moments, to be sure. He famously anticipated Apple's iPad a decade before it was built. His work on eradicating polio is likely to offer insights on the potential of new technologies. That may actually be useful when it comes to turning Microsoft into a services company. But Gates's stated role is to be the product guy to Nadella's service-centric background.

Most of all, the selection of Gates as a technology adviser is further evidence of a dominant insider's culture that some worry will hold back the effort to shake up the company.