I dont believe the July date either, but you have to understand that EAP is not FSD. Meaning, they are not based on the same core set of functionality. EAP is just TACC with lane keeping. It sees cars in front of it and lane markings only. Even Level 3 FSD will use high def mapping and more vision to see things like signs and understand cars vs trucks.
EAP was a hack to replace Mobileye in a hurry. FSD is a whole different monster and requires a lot more time. The additional time is not so much developer time, but more machine learning time. The system needs to see billions of signs, cars, road markings and other images to learn what to look for. In addtion, high-def maps also need to built which requires all those same images as landmarks. Landmarks are used to take 1.5M-3M GPS to a 5-10cm accuracy. The system will rely less on seeing lane markings and more on paths in the high-def maps. If you know where the car is in the world down to 10cm, then you dont need to see the lanes, even in heavy snow. The vision system will be the backup to the high-def map in this scenario and will be used to find landmarks that help the system know exactly where you are in 3d space. The vision and radar will also be used to identify objects that are in your way like cars, or a child darting out into the street. Once those three things come together for the freeways, they can enable Level 3. Once proven out and more areas are mapped in more detail, then Level 4. Once Level 4 proves to be safe, it will be allowed in more and more places and situations like heavy snow and at some point, fully validated as 10x safer then humans. At that point then Level 5 would become available for regulatory approval, which I think will actually come fast. States and the fed are falling over themselves to be the first to approve autonomous driving to save 20k lives a year and I think they are already working on requirements.
My guess is Level 3 by Nov/Dec after the demo. Level 4 - 6 months later. Level 5 - 6 months to year after that in most parts of the US and Europe with other countries to follow as more data is gathered and incorporated.