Disney (DIS) shares rose Monday following news Bob Iger replaced Bob Chapek as CEO, effective immediately.

And the longtime CEO's impact is already being felt upon his return.

On Monday, Iger made his first big move as CEO — firing Kareem Daniel and restructuring Disney's Media and Entertainment Distribution (DMED) division. DMED was one of Chapek's first big swings as chief executive, but the reorganization was categorized as a controversial move that upset longtime veterans and reportedly "confused" workers.

"Over the coming weeks, we will begin implementing organizational and operating changes within the company," Iger wrote in an internal memo obtained by Yahoo Finance and sent to employees on Monday afternoon.

Iger added: "As you know, this is a time of enormous change and challenges in our industry, and our work will also focus on creating a more efficient and cost-effective structure... Our goal is to have the new structure in place in the coming months. Without question, elements of DMED will remain, but I fundamentally believe that storytelling is what fuels this company, and it belongs at the center of how we organize our businesses."

Wall Street analysts, at first glance, appeared optimistic Iger's return will improve the fortunes for a stock that lagged the market during Chapek's bumpy tenure. But the decision still comes with its own set of risks.

"The transition does create some uncertainty that we all need to be mindful of in terms of the strategic shifts," Kutgun Maral, analyst at RBC Capital Markets, told Yahoo Finance Live early Monday, before the news of Daniel's departure had broken.

"Even though the longer term opportunity remains very attractive, we still need to see what the next steps are to better evaluate the near to medium term implications to shares depending on whatever path Iger takes for his mandate for 'renewed growth,'" Maral said, stressing the Board's decision suggests more urgency in positioning the company for the next decade.

Maral referenced the company's press release, which noted Iger will serve as CEO for two years, with a mandate from the Board to "set the strategic direction for renewed growth and to work closely with the Board in developing a successor to lead the Company at the completion of his term."

"I think investors would like to see, over the next two years, greater articulation and reshaping of [Disney's] plan with the creative side of the business," the analyst said, adding that pricing strategy and the evolution of its direct-to-consumer portfolio will be top of mind as well.