We now have a big unplanned experiment. We will see within the next few days if the protests lead to significant spikes. Personally, I think that the virus probably doesn't spread that easily outdoors, so while we will see a spike, it will be small enough that it will only make the case for opening up outdoor activities sooner. Fingers crossed.
I'm not sure if this is a big unplanned experiment any more than states already opening up and existing protests for opening up have already been doing.