There have been rumors of Disney land purchases in Texas nearly since Walt announced the Florida Project. This one's either April Fools or just the constantly-recirculating rumor.
In terms of economic analysis, there is simply no room in Disney's business strategy to build a park that siphons-off business from WDW. First off, if it did result in smaller crowds at WDW, the company would be losing money. The more people they pack into the parks and resorts, the more money they make, and most of the money is made on the top end - the difference between 85% average hotel occupancy and 92% in terms of profit is huge.
A Texas park would have little impact on Disneyland, but in terms of airline miles, it can be a coin toss for a fair amount of the population east of the Rockies. How many would choose a two-day visit to a Texas Disney Resort, vs. a 5-day stay at WDW? Perhaps enough to not only shift attendance from one place to the other, but to actually reduce the average number of days folks spend on their Disney vacations. What's very clear is that there is not pent-up demand for theme parks in the U.S. - certainly not enough for a Texas park to find a substantial number of all-new customers.
Meantime, Disney Parks and Resorts has (or will soon have, I should say) a presence in the Texas market - the Disney Magic, which will be sailing seasonally out of Galveston for at least the next two years. Unlike a park, if the cruise line doesn't do as well as hoped, they just sail the ship elsewhere.
Co-Author, PassPorter's Walt Disney World, PassPorter's Disney Cruise Line, and PassPorter's Disneyland and Southern California Attractions