As to the bolded - this is an if, not a guarantee.
Under legacy, if I was at RD, I got a fp for whatever I wanted, guaranteed. An hour later may be different, but *at RD* it was guaranteed.
Under fp+, if I am online when my 60 day window opens (the new "rope drop" for fp+), it is not a guarantee that I will get a fp+ for whatever I want as the full fp availability for the day I'm scheduling is no longer available. People who are there during my trip, but check in a few days before me have already started depleting the pool.
Yes, this is only true for a few things...but the same could be said for legacy where only a select few attractions ran out of fp for the day quickly. Under legacy, I could alter my.touring plan the next day and be there at RD and get a fp if I wanted. Under fp+, those hard.to get fp+ were booked up long before you set foot on.property.