The Twitch video was recorded last september (2014), how fast do you think they planned, designed, coded, tested and published the Community Goals ???
DBOBE would have been fully aware of CG when he did that presentation. Maybe not down to the smallest details, the main bulk and idea would have been on a planning board somewhere in the office.
Michael Brookes posted asking for people to test CG in Feb 2015 by the way - I doubt they put all the together in under 5 months
https://forums.frontier.co.uk/showthread.php?t=108889
Definitely CGs were probably on the horizon at that point, and I agree with SteveLaw (as I have done before on this matter) that CGs are not player-to-player interaction. Furthermore, there definitely is a feel of, if not cooperation, at least not to hinder each other; first because the better everyone in general does, the better it is for you, second because it wont help you in the rankings because you wont be fulfilling the CG yourself.
However, Powerplay
does seem to imply a conflict between players. It was not likely at the forefront of DB's mind back then (if indeed they had even thought about it at that point as more than just a future possibility). Hence, one could say that DB's comments in the twitch feed (which in context really do seem to refer to griefing) on PvP probably did not apply to Powerplay.
As for the thread comment, thank you. Everything in that answer strengthens my belief that PvP is something they are looking at seriously now, as opposed to "rare". The question is a concern on just how expansive PvP may become. The answer to me is defensive, rather than refuting; basically a version of "Yes, there will be more, but it wont be everywhere".
On the other hand, it still isn't the same as saying they will go to the effort of supporting PvP, in the appropriate Powerplay events, if something is detracting from it. As I have said, and others have expressed in their own ways, I am concerned that the efficiency (through nothing providing a challenge/obstacle) of Solo will basically result in "if you are serious about Powerplay, you play in Solo". Again, since I feel I have to be defensive on this, I do not want Solo to suffer in any way in order to combat this, if indeed it does become an issue. Any solution must take that into account.