I think it depends on what they mean by "open up"...DCA will often open the gates early to allow guests to get through the ticket gates before park opening. Guests are held in the Buena Vista Street area until the park actually opens (at the posted opening time).
Buena Vista Street (BVS) is like Disneyland's Main Street. Meaning that everyone walks up the street as they enter the park and then from the hub/water fountain area, guests can decide which "land" they want to head to. Before park opening, guests are able to go into the shops and dining location on BVS, but they aren't allowed to venture further into the park (there are CMs blocking the walk-ways into the various lands). When the park opens, the CMs allow guests to head to the various lands (e.g., Carsland, Condor Flats, Hollywoodland, etc.).
In terms of RSR, yes, the recommended method is to use the "Wide Right Technique" if you're in the front of the pre-opening crowds.
The language is careful not to say that any of the attractions will be open, so I think they're just referring to the ticket gates. My experience is they generally do allow guests in anywhere from 15 to 30 minutes before the posted opening time.
a 1st-timer question...
Are guest services on BVS (Chamber of Commerce and the Camera Shop) open before official opening/rope drop? I am trying to figure out whether I can pick up buttons (birthday button for my daughter) and Photopass+ larnyard while waiting for rope drop.