They are a business - they are absolutely using e-nights where a profit is most likely - same would apply to EE.
The question is, are they ACCURATELY assessing the long-term impact of these moves.
Whether the cut is earlier closing times, EE, or E-Nights, its clear that cutting any of them costs them revenue. The only question for Disney is figuring out how much it will cost not only today, but next year, and even 3-4 years down the road.
Since most WDW visitors don't come more than once a year, and don't follow these developments very closely, they are probably not aware of cuts until they arrive. So the short-term impact to the bottom line is a positive one. Very few cancel, and money is saved.
But will they come back as soon next time? Will they stay as long? Will they stay off-site instead? Disney won't know the definite answer to these questions for as long as 3-4 years after the cut is made.
Earlier closing times have been a gradual trend for about 4 years now. EE has been gone about 9-10 months. Enights have been reduced in slower times for 9-10 months as well.
There's a very real and very serious danger in this whole scenario: WDW makes a few cuts and sees the positive impact to the bottom line, and thinks it can make a few more cuts. Again, a positive impact to the bottom line. This process goes on for 3-4 years, and each cut looks good because the short-term benefit outweighs the long-term loss in revenue.
But at some point, too many cuts have been made. The short-term benefit does NOT outweigh the long-term lost revenue anymore. But since the lost revenue won't be noticed for a few years, Disney thinks everything is hunky dorry, so they cut some more, unknowingly going further under the cost/benefit line.
By the time the revenue hit has been felt, they've gone way below that delicate balance, and will have to live with the negative impact of their decisions for several years, even if they reversed every cut they made. For just as it takes time for the cuts to be felt, it will also take time for adds to be felt.