I imagine that modifying the controls for either ride would require additional cost from the manufacturer or control system providers to interlock them as well as additional state inspections. By making a phone call or providing a video camera to observe the other rides operation by passes all of this extra cost on the control system end since both rides still operate the same way as they were designed. It is just up to the operators to manage the dispatches.
So many interesting infrastructure questions! I would think that using wifi (private or not) would not be very desirable for reliability reasons. I would think the park would have a lot of fiber optic cable running all over the place in order to support a number of different things at this point (phones, points-of-sale, security cameras, etc.).
Nope nothing new. I think they will at least do a media day so that they can show off the ride to the media and let them talk about it to their audiences. For the people who raised the money for the benefit, I think they'l do something. It might be a multi day thing so that they don't have huge crowds coming at once. Probably depending on how much you raised.