He actually didn't say that. His interview is here:
http://www.denofgeek.com/tv/doctor-who/37736/doctor-who-series-10-shooting-to-start-later-than-usual
Direct quotes:
"Well, that won't start until... you know, well into the new year. It doesn't start shooting for a short while. And so, it will be - you know, probably - February, March before we start getting onto the next one."
He also said that his start date could be "a couple of months" prior to shooting, before back-tracking a little and suggesting that such a situation might be "a luxury."
These statements have led some websites to speculate that series 10 won't go in front of the cameras until 'May 2016.'
Admittedly, if Pickwoad's design work isn't starting until February or March, Doctor Who series 10 certainly isn't operating on a carbon copy of series 9's schedule.
But it's worth noting that Pickwoad didn't say the words 'May' or '2016' at any stage in the interview.
So it can happen like you are believing, but I don't think we should be so sure yet.
There's a few possibilities:
1- Full season in 2016.
2- Season starting with the Christmas special and going back to the old schedule in 2017.
3- Split the season in two parts.
None of them actually confirmed so far. Let's wait and see.
EDIT: Oh, and Capaldi denying half the number of episodes in 2016 may discard the third option there. Meaning either split season or short season. Both fit for that description.