Funny, I was actually typing a response to this when you tagged me.
Ok I don't know how I feel about that change. At least from a technical planning and park logistics view. But there could be value here too. Not really all that sure yet.
So logistically, removing the entrance corridor just isn't done for a lot of reasons I think. Most practically, there are a lot of services that need to be held at the front of a park and that means buildings are needed. Cynically, the entrance is the place to maximize retail and other guest services based on observed guest traffic patterns. People buy on the way in and the way out, and frankly in a theme park, guests want to find the retail on the way in and the way out because they've been trained to find it then and there.
Sure this stuff could be placed outside of the park in an open retail zone, but then there's a bunch of new issues. Security and open access, contradictory themes and styles, control over the total experience, guest habits. I mean with this plan a guest would have to exit and then re-enter the park to buy merch and food, and then would be competing with non-guests, non-Disney stores, and a non-Disney theme, making an inferior experience. Just seems like a situation where if it could be in the park, it would be better for the guest experience to keep it in the park.
But besides the logistics, there are experiential and spatial values to a single entrance corridor and its basically why all the parks do it. This is more of a point to how the garden is planned out, not that it is a garden. Guest understanding of the park is easier with the single pathway leading to the center. Easier to get lost on the way out if you could have taken a bunch of branches on the way in, so having a single and very obviously emphasized path helps a lot. I mean I've heard stories of guests having trouble finding the entrance and exit of Animal Kingdom because of how the path is somewhat meandering with a single split.
Also, in a spatial compression and release aspect, the narrowness and single experience of a entry path is really effective at moving you into the park physically and thematically. The Disneyland style park entrance is a series of compressions and releases that essentially squeeze you into the park with really clever visual tricks. In a tight space, you want to move forward and then in the resulting open space, a view draws you into the next compression, over and over and over down the street. If you don't feel the need to move on, the front of a park could maybe end up with a crowding issue. And the tightness of the entrance quickly pushes your into the theme mindset because your are enveloped in a single, completely non-contradictory space, except for the park icon ahead, which is that visual that pulls you forward. I think there is value in being enclosed in a story to start of the park that would be lost in a garden that looks over to 2 or 3 other lands at once.
So those are my two points. But #1 does not mean that you cant have a garden, just that I think the outside retail (or at least only outside retail) is a bad idea and #2 does not mean that a garden couldn't fulfill those goals if designed right. It definitely could.
So this is my way too long way of saying that it probably could work but as a part of a larger entrance sequence. If you want Downtown Disney right next to the park, you could do exterior retail zone > park gate > interior retail zone > single entry corridor > Fantasia Gardens > Castle.
Which just so happens to be exactly what Shanghai Disneyland did. So yeah, that's my thought about that change.