If you click the link you will see that Cozmo only answered part of the question. The final question in the quote Cozmo pulled from Lost Sols goes something like this:
Will players who've not purchased the Taken King have access to currently existing endgame content once Taken King releases? Yes or no?
To expound: will they be able to play nightfalls of the currently existing content that exists today on 8-28-15 on September 15th? And the dailies, and the weekly heroic, etc.?
Yes or no?
Or will they be locked completely out of those activities because they didn't purchase TTK? Activities that would include Vanilla, TDB, and HOW content.
Here's the full quote:
Lost Sols-"Say what?
You really are going to end with that? So what does that mean, because people are freaking out they'll have to beat the raid to play endgame (unlikely, but can easily be inferred from your remark). Are you saying that unless we purchase TTK that all endgame will be completely locked for us?"- Lost Sols
Cozmo-You don't have to complete the Raid to play anything. The Raid is the pinnacle of end game activities.- Cozmo
No answer from cozmo. Oh well. I got the answer from the most recent game informer interview via youtube.
If you do not purchase TTK you cannot play the daily, nightfall, or vanguard heroic and normal strike playlists.
Why? Because you won't meet the light level requirement. The light level requirements can only be met through equipping powerful new taken king gear.
You will start at light level 160. The nightfall and strikes are above 200. No taken king gear, no access.
Question answered.
https://youtu.be/UCd14QkmV94
Final edit: you can't lvl past 34 without TTK. It's clearly stated in the patch notes.