AP holders will still come. Local, day guests might not. That ticket special is being heavily advertised, along with "Rise of the Resistance--NOW OPEN." (Like, in the same commercial) But, if it's a gamble whether or not you will even get the chance to ride the new ride, THOSE people may decide it's not worth it. Think of all the people who may take advantage of the tickets knowing they have as much of a chance to ride the new ride than any other ride in the park. Once they find out that's not the case, they are bound to be pretty annoyed.
Here's the thing. EVERY other ride
Disneyland has ever opened has done just fine with a standby line and fastpass. I don't really understand the justification for using this system on JUST this ride. They built the queue large enough to hold several hours worth of a standby line. Disneyland guests tend to be fine with standby waits up to about 3-4 hours, as evidenced by RSR. They are okay with that. What makes anyone think this ride would suddenly command such drastically longer standby waits long term? Look what happened with MFSR...waits were crazy initially but have settled to 30-60 minutes on average. The line will regulate itself.
This Boarding Group system is nothing more than Disney trying to squeeze more money out of guests by keeping them out of a long line. However, rides need people in lines, in order to keep the crowding to a minimum in walkways. If no one is in line, and you have thousands of people loitering in SW land, sitting against buildings (NOT spending money, as happened yesterday), all that is accomplished is making the park feel cluttered and mismanaged.