They have/had a subsidiary owning a distribution center in Irving (I think). That subsidiary just happens to have the same corporate address as Amazon itself does. Amazon is walking on very, very thin ice on its claim that it doesn’t owe sales tax.
If Texas is successful here, look for Amazon to only have distribution centers in states with no sales tax.
The Texas Controller will be successful in killing several hundred jobs in Irving, which will move to a 0% sales tax state.