we've been there 3 times since FP+ started, and twice while the tiering was going on.
Near as I can tell, the whole purpose of both tiering and putting fastpass + on rides that rarely had lines is to create a more balanced crowd throughout the parks. But the way they are doing it is engineered crowd-management for sure. In some cases, they have put in long stand-by queues where they are not needed and having people walk through the long queue even when no one is in line. We saw that at Philharmagic, Muppets, Great Movie Ride, Peter Pan...used to be if no one was actually in the lines, they would move the ropes & poles so that the stand-by skipped all the switch-backs and you more or less walked very directly through. These last two trips (October and early December) they had all the switch-backs incorporated in the lines, and you had to walk through every square inch of possible queue line even though there was no one ahead of us, and no one in the fastpass entrance. Like at Great Movie Ride...walked through all the outside queue line, then through the whole inside...and got to the holding room with the movie clips...it was empty. Completely empty except the castmember at the front podium. So there was absolutely no reason to have you walk all the way through all the outside & inside queue lines...except to make it inconvenient for stand-by. Basically, they made it a lot more work to "do" the stand-by...our impression was they were making the stand-by worse than it needed to be as a way to encourage people to think that the fastpasses are all valuable, even for 2nd and 3rd tier rides. If you'd never been there before, you wouldn't know that they used to shorten those stand-by lines when they were not needed for crowds.Now, all you notice is that the fast-pass line walks directly in, but the stand-by requires 10X the walking, so Gee, next time I'm going to get one of those wonderful fastpasses and skip all this awful walking!
And those FP+ for the 2nd tier rides...our experience at Epcot on a relatively slow morning, at rope drop, was they most definitely are spreading the crowds out by suggesting the need for fastpasses on the lesser attractions. In the "old days", virtually everyone in the the rope-drop lines would head for either Soarin' or Test Track... leaving all the "lesser" rides as virtual walk-ons. This trip, though, here's what we saw: first thing in the morning, Soarin and Test Track were walk-ons of course. BUT 20 minutes after the park opened, both of those rides were up to 40-50 minute stand-by. The odd thing was, so were Journey into Imagination, Spaceship Earth and Nemo/The Seas...all had 30-40 minute posted stand-by (and actual lines, too) We couldn't believe it, the line for Figment coming out of the building and curving around the side on a slow morning at 9:30! We asked the castmember later in the day (when it was again a walk-on) if the ride had been down that morning and she said "No. That's the way it is now, with people booking fastpasses first thing in the morning. Now all the rides get people right away so the stand-by backs up." According to her, that was the way it was supposed to work, spread the people out for a more balanced crowds and lines everywhere...so the "big" rides don't get overloaded while people ignore the other attractions.
The bottom line for us...all this crowd engineering just meant that we did less attractions in the same amount of time on slow days.