getSelectedItem was deleted in 2018 (see 291f26c4470d, T76630). However, searching "getSelectedItem" still gives 3 results, and the function is even found in the example on top of OO.ui.DropdownWidget:

dropDown.getMenu().getSelectedItem().getData(); // returns 'b'

This is extremely confusing and took me a lot of time to figure out 🙃. The doc says Generated on Thu 20 Sep 2018 21:47:28 by JSDuck 5.3.4., can we update it since it's already 2022?