I actually really like the idea of a short season. I know it seems to get a lot of American viewers very worked up, but a shorter season with a more focussed story seems much better to me than the highly variable 22 episode season that is the US norm. So a 13 episode season with each season moving forward a year sounds like a great format to me.
Another bonus is the potential to get a better grade of actor to appear in the show, because that shorter commitment doesn’t preclude them from movie work.
Although it’s not the sort of format that #ABC normally follows and that fact they haven’t said yes or no to a pilot script yet is a little worrying.