Here's what I can confirm:
I'm an AP holder so I can book for any day whether I'll be at WDW or not. We're coming down on Wednesday.
I went into FP+ through disneyworld.com (via Safari on a Mac).
I choose tomorrow (3/30)
I selected the first three attractions (Small world, Buzz, Thunder)
The next screen is the one with 4 options (A-D with different times) and on this screen I had 4 FP listed. Philharmagic was the 4th FP that was added.
I did the same thing for 3/31 and again I had a 4th FP added (but I don't recall which it was).
I did not try for 4/1 because I already have FP+ scheduled for my trip. I did try to "update your FP+" but I only had my original 3 listed. There was no bonus 4th FP.
We are leaving on Monday 4/6. So I tried to add FP+s for Tuesday 4/7. I selected three rides and when I went to the next screen with the 4 time options (A-D) there was not a bonus 4th FP. There were only the three I had chosen.
The Force will be with you....always.
Based on what you're saying then those who did in fact book in advance at either the 60 or 30 day marks are at a disadvantage for the "test" . Yep makes sense = Not !