I do not want again to play the devil's advocate, but as far as I remember these few seconds are showing the J-20 during its maiden flight side by side with that famous J-10AS chase plane.
Yes,you are totally right it is the footage of its maiden flight. However, this is the first time that this footage is appeared in that CCTV International Channel (targeting overseas audience) in the news piece about how the most elite air division of China Southern Theater Command, whose main duty is to deal with Taiwan crisis.
If people who spend time to watch the footage and understand what it says, then perhaps you could place your emphasis more on the whole context instead of the image itself. My conclusion was made, not solely on that J-20 footage, but by the fact that its was shown in that news for the following reasons:
1) CCTV is a very strict government organization, any news is subject to tight scrutiny, let alone these types of news about Chinese elite air division exercising breaking the first island chain and new battle capabilities;
2) The editors want to imply that J-20 is already arrived in this division by showing this maiden flight footage because the production vision is still top secret.
3) There were news months ago that China air force completed its polite training facility for the special "seed division";
4) There was a blog news months ago letting people to remember and celebrate a day as the most important day in the China Air force history;
5) J-20 has to be in service before 5.20 (Taiwan election) and 2016 year end (F-35 in Japan). These are the main nodes in its development.
I could be wrong in my reasoning, but that is all what we could do in relation to this top secret project.