Just think, Disney is building and building and when Universal finally announces their 3rd real gate Disney will respond by announcing an even bigger building program. They will expand MK, build a new land in AK between Africa and Asia, and announce the changes and expansion in Epcot. Plus thousands of new hotel rooms.
Will Universal gain market share? I doubt it. They may grow to a 4 gate resort with 15,000 hotel rooms, but Disney will expand even more. Universal will be capped with a total of about 50 million a year in attendance but Disney can expand its 4 parks to well over 80 million and still build 2 more gates.
In any case no matter what Universal does WDW will draw over 65 million in 2020 and 70 million in 2021. MK will continue to draw over 20 million a year. AK will draw over 15 million as will Epcot with the additions of Guardians of the Galaxy, Ratatouille, ride in England and the surprise coming in Wonders of life. Then their is Hollywood Studios. SW:GE needs an expansion and looking at the land the space is available for a major phase 2 to SW and more. The potential is so big for SW that Hollywood Studios could pass MK in attendance with proper expansion. That is why MK will be expanded beyond it's current foot print.