The popular press report says that washing doesn’t make a difference. The actual, paywalled study says they did find a highly significant interaction between washing and type of rice, which is a level of statistical sophistication that a food writer might not grasp. In fact, even the scientific authors seem not to have commented much on the interaction.
In their data, it looks like washing 0-amylose glutinous rice makes it more sticky, while washing medium-grain 21% amylose rice even just 3 times makes it less sticky, and that 13% amylose Jasmine rice is just kind of all over the place or not systematically influenced by washing. They didn’t do a big table of adjusted post hocs, so it’s difficult to tell which specific groups are different from which others.
They also cooked the rices differently, using 1:1.3 rice:water for the glutinous and 1:1.6 for the medium and Jasmine, which obviously might confound their observations.