Looks like Jaakko Roppola himself confirmed your saying.

From this article : http://www.engadget.com/2014/02/25/j...artphone-mold/
"It's one of the reasons why future incarnations of Jolla's Sailfish devices will retain that two-part modular design. As Roppola explained to me, the company wants to avoid the "culture of throwaway devices," which a shift to a unified design might encourage."

I understand this position, but doing so, it leaves me not much hope for the next device as I don't really like the current form factor (but seeing the devices presented at the MWC, it seems I am the only one)...
Anyway, we'll see. It is a bit early to take conclusions.

Edit: I didn't see there was still some text after the photo
Marc Dillon is a bit more hopeful : "New form factors are on the way, but much of the heavy lifting will be done through manufacturer partnerships"