Here is the quote from Cheshire Figment
He says that it will save Disney money if people with expired FPs don't get in the line at the end of the day. He knows what he is talking about and he specifically mentions not just the CM at the attraction in question, but Custodial, Greeters at the Gate, Security, etc.
When they eliminate those extra long lines and extra time from ride operations, but they still let me linger 2 hours in the world showcase, or shopping on main street- then there is no net savings when it comes to custodial, greeters at the gate, etc.
If one of the reasons that they are eliminating late FP usage is because they want to save money in CM pay at the end of the day, they aren't going to be able to do so if I'm still in the park shopping. That is why I am concerned.
That person may have been told something along those lines, but that's a patently bogus idea on its face. First off, Disney World parks NEVER "close" ... Yes, they close to guests, but (paid) staffers come and go 24 hours a day. It would actually take a great deal of work to ever find a moment, forget about a significant chunk of time, at Disney World that any park was completely "empty." Maintenance, janitorial, prep work, decoration, gardening, etc. ... All go on throughout the night. Every night. 365 days per year.
At any attraction/position, Cast Members shifts overlap to allow some to leave while others stay, and every single attraction is staffed with the idea that Cast Members will be on the clock well before, and long after, park closing. Schedules are set up that way to prep and/or shut down the ride.
Second, and most germane to this discussion, there is nothing stopping all those "late FastPass holders" who may be denied FastPass access from just getting into the standby line for the same ride, with the net effect of the ride's total operating time being exactly the same. Disney allows anyone to get in line, FastPass or standby, up until the park closes--and sometimes even encourages it with Cast Members calling out to park guests and offering 'one more ride'--and guarantees all in line will ride.
So, the idea that this is to finish up more quickly is absolutely ridiculous, not only for the reasons already stated, but also because Disney also allows people to shop, dine and wander the park, even if they don't allow them on the attractions, for long after a park's official closing time. You would have to spend more than two hours in a closed park before anyone even STARTED to sweep you out, assuming you weren't causing a ruckus, or doing anything else (trying to get backstage, etc.) prevented by Disney. (The exception to this would be when the park closes for another event, be it private or hard ticket, and then sweeps begin almost immediately.)
The truth is that the end of operating hours is THE most lightly-attended segment of the day at virtually every park, all year long. And since you have to be IN the park to use your "expired" FastPass, and most people no longer are, the effect on ride end times isn't just negligible, it's nonexistent. If you're IN the park and get in line at, or just prior to, closing, you can ride, period. FastPass or standby line, there's zero difference in actual use. It's not as if people with FastPasses were given special access to closed lines; or the ride operators were "waiting" for all FastPasses to be redeemed before shutting down for the day.
You could argue that fewer people would stay in the park if they weren't holding a FastPass but there wouldn't be any data yet to back that up and Disney isn't in the business of driving guests OUT of their parks at any time of the day (or night), so that would be a negative, not a positive, for the company.
I'd say it's far more likely (since we've done it) that you get a FastPass, thinking you'll still be around, and then never use it because you petered out and headed home long before the start time came around.