From the conclusion: >Charge is therefore to be understood as a local compression of the metric in the spacetime, which relates to longitudinal waves as described in [12]. This provides some aesthetical features into the model, as electromagnetism seems to be orthogonal to gravity in the sense that current theory of gravity is a theory based on metric compatible connections.
From what I can see, this is just a particularly obfuscatory way of saying the same thing I said in response to philipov upthread, where I described how there are different tensors in GR to model gravity and EM. It's not in any way a theory that derives EM from properties of the metric tensor. It adds additional degrees of freedom that aren't in the metric tensor, and then tries to obfuscate what it's doing.
But it can't be quite "the same deal", because gravity obeys the equivalence principle, and electromagnetism does not. (Nor do the other known fundamental interactions.) The paper does not appear to address this at all.