No , that has nothing to do with it. It always worked this way, only now people take a closer look at it because of the new background.
Cepi Perez made it based on pressed and released events. To get the stock clock behavoir, it's needs to be based on clicked events.
I am now combining these three, so I also can preserve the pressed icon effect.

For now it means more work for me, but that's okay

If you use the latest hildon desktop, that is no longer the case, because of the Qt fixes of Arcean. But the (cssu based) settings program was able to adapt to portrait earlier.
I have looked at that a long time ago and even posted a question about it on TMO. It is now even capable of showing the worldmap in portrait in noticed some weeks ago! I scanned the code then, it makes a similar call like I do. I didn't figured out how it was done. One big difference is that "settings" is based on GTK, so it may be some GTK magic.
Maybe Pali or Arcean know more about it.

P.s. if you use forced portrait mode, exiting the work map from the applet will freeze the replacement clock. So it is better to use it from "settings" anyway, until it perhaps will better integrate in the replacement clock.