This is the relevant quote:

    "But from a deep, fundamental point of view, this is  
    nothing new," he says. A gravitational field is merely 
    another environment to interact with, so invoking it 
    does not explain whether quantum behaviour might lead to 
    classical reality if gravity’s influence were 
    mitigated—for example, by doing the experiment in 
    gravity-free space.

It's an interesting piece of work, but doesn't seem to add anything fundamental to the discussion of gravity and QM. It just shows how gravity can result in decoherence if different parts of the wavefunction experience different clock rates due to gravitational fields.