At the end of the day, the effectiveness of the protective measures will come down to willingness of guests to comply with the measures.
We've talked a lot about how even if they make masks mandatory, some guests will refuse, and if they make them recommended, even fewer will wear them.
We've talked about how they can make the parks have marked "lanes" and make everyone go in one direction, with one entrance and one exit at stores and lands, so that social distance is maintained, but guests will have to follow them.
We've talked about queues having markings that indicate where to wait, but again, guests have to comply and follow it to maintain social distance.
We've talked about how guests will have to take responsibility for frequently washing their hands, and again it's up to the guest to comply.
Each of these modifications is not super effective on its own, but if everyone complies, all of them together is more effective than not having them. But, again, guests will have to take responsibility for taking the time to follow the directions, follow the walking directions and wait markings, put on a mask, and take time away from fun to wash hands frequently.