The phase of signal when it passes a frequency divider?
That can't generally be said. It depends on the actual design of the device. 

In fact, it's not going to be constant for all frequencies, because that's physically pretty much impossible to achieve.

You'll find multiple descriptions in literature for three- and four-port devices like these, and you'll have to learn how to infer the relative phases for different frequencies from the measurements that the manufacturer of a divider will provide to you.