Let me point out that 15,000 construction jobs is actually 1500 jobs over ten years, or 15,000 job-years. (More likely the project would stretch over decades, thus employing fewer people at one time.) Also note that there's mention of how "Brooklyn" needs the project, but no mention of developer Forest City Ratner.
There's nothing wrong with the unions pursuing their interests, and Forest City Ratner, whether for reasons political and/or to ensure quality construction, has committed to union labor (though not for demolition).
One difference to remember, though, is that labor unions have been a part of Community Benefits Agreements (CBAs) in Los Angeles, while in Brooklyn, the CBA was "negotiated" with hand-picked groups rather than a full spectrum of the community affected. Thus labor, not part of the AY CBA, did not have to balance its interests with the concerns, for example, of environmental groups.
The battle on video
Interestingly enough, the "related videos" appearing on YouTube all relate to criticism of and reform of the project. Perhaps, as the Atlantic Yards battle continues, we'll see a proliferation of videos.
A spokesman for the union confirmed that this was a union production, without the involvement of Forest City Ratner.