this is a long thread, and I didn't read it all, so at the risk of reiterating ideas and sentiments already expressed, here are my thoughts...
Of all the changes Disney has been making, and I understand they need to during Covid, the loss of Magical Express, baggage delivery and Resort Airline Check-in are the ones that hurt the most.
Not having to grab our checked bags at the airport, and not having to find our way to the resort and drive to it (even if by GPS), along with getting boarding passes and checking our bags at the resort before heading to the airport on the way home set Walt Disney World vacations apart from other destinations.
For those coming from other countries, they didn't have to worry about our driving laws, finding their way around in a new location, etc. Can they use their phone as a GPS in the USA (they'd have to have a data plan that works in the USA).
This move raises the over all complexity and cost of a family's trip.
As a family with only 1 child, it was nice for us to only have him, his stroller and our carry-ons to worry about once we checked into our home airport. When we landed at MCO, not having to then also deal with our checked bags, a car seat, rental car, etc. was a blessing. When he was 1.5yrs we did do a trip where we stayed off site, we had my sister-in-law and her BF at the time with us. It wasn't as much fun even with 4 adults looking after him. The airport was new, so he was curious and wanted to explore! Now that he is 12, its much easier for us. We don't have a stroller, he can pull his own checked bag, etc. But our November 2020 trip was still not as fun, having to collect and bring our checked bags, and no airline check in on the way home so we had to stop at the airline counter before going to the TSA screening. The only reason we didn't use the Magical Express this trip was a friend from South Carolina joined us, so she picked us up at the airport along her way.
Consider a family of 4, with children 6 and under. They will need 2 car seats, and likely have strollers in addition to their bags. Managing all that becomes more stressful and difficult. They would need a larger vehicle to fit it all. So if they did a ride share, their options could be limited, and more expensive. Not all "Suv's" are created equally. Suppose one that can't hold it all arrives? what if the driver doesn't have enough car seats? Or what if the driver keeps car seats in the car, but its a family who doesn't need them, so there is less space for luggage, etc. Btw, what happens with Uber/Lyft if your flight is delayed or changed? do they wait for you? Do you have to call another and wait for it to arrive?
If a family rented a car, their costs could be higher too. (last time we needed a car seat was years ago, at that time Hertz charged for car seats, and it was more expensive to rent a mini-van than it was a car, or smaller SUV like a Chevy Equinox).
For those who use travel agents to book their Disney trips, will the TA be able to book the ground transportation for them, or is it up to the family to handle?
I also can't imaging the number of passengers arriving each day, trying to get their luggage and then taking rental cars or ride shares. Does MCO have the space for all the ride share drop offs/pick ups? How easy will it be to find your ride share driver/car in a sea of other people trying to find their ride? When it comes to rentals, Does MCO have the space to store the additional rental cars that will certainly be needed? With the advent of some rental companies doing a "skip the counter, grab a car" I would expect car rental counters to be crowded, but not overly so. With the demand for more rental cars, will rental prices go up? And what about more traffic between MCO and Disney with the extra cars?
I'm not confident Disney will introduce a service to replace Magical Express. If they had one, they should have announced it with the cancellation of ME, to head off the negative feelings created by this announcement. The Brightline train from MCO to DS wont be a solution since its not going to be ready until 2022 (assuming no delays). It wouldn't be a good experience. You'd have to depart the Airplane at MCO, presumably visit baggage claim to get your checked luggage, wait on & a board train with your luggage, disembark from train with all your stuff at DS to wait on resort bus. Think how long that will take. And if your room isn't ready, wait on a line at bell service with all of your luggage for them to hold your bags. Oh, and those complaining about "3hrs (4 at xmas/new years) before boarding" ME back to airport... this arrangement will probably take even longer.
I can see this as a money maker for Disney. They no longer have to cover the cost of ME transportation, baggage handling, and distributing boarding passes and "Tragical Express" envelopes. And they get income from those renting a car who will be parking at the resorts. Oh, and they might be able to get a deal from a rental company to promote them as the "Official Car Rental Company of Walt Disney Word" (I realize that Enterprise, Alamo or National have desks at the WDW Car Care center, but are they "the official car rental..." ??)
As for the 30 Minutes Early Entry... Its a trade off. Sure its nice that it is now consistent, every day, every park, so you know what to expect. However having an hour before park opens, or an hour or two after park closes, allowed for getting more rides in during the EMH. So I am kind of torn.
With this change off-site guests will be unable to rope drop. Of course that is a disadvantage for those staying off site, or who are locals. That may eventually drive more guests to on-site stays. If that happens, Disney will have to adjust their timing and add more resort buses to handle the extra passengers in a timely manor to ensure resort guests can fully take advantage of the perk!