Then what will you say for iPhone 5s
iPhone is different, I was referring to update cycle pattern. The product segmentation from Apple differs vastly from Sony. Z1 shared the flagship crown with Z Ultra and Z1 Compact, whereby they were flagship compact and flagship phablet respectively. In case of Apple, 5s was a single piece(5c....completely forgettable), and hence by default a true flagship. Z4 as such cannot be considered one, given the low profile release and no global announcement. I think they want to keep the 6 months release cycle, with complications of having devices in market selling at similar price(Z2 and Z3...not much difference in specs and price). Either Sony is trying to close all the loops and planning to end its mobile operations, or they are creating something in lines of Galaxy S6, a rather radical Z5.
Honestly, I don't think Sony can pull another Motorola, given that Kazuo Hirai is more interested in sensor and playstation business, rather than focusing on core Bravia and cellular business. I can see another Sharp in making, a company more focused on providing OEM components and niche consumer electronics. Can't blame the management too as it is imperative for them to show profits, but neglecting divisions is a bad way to end them.