First I've heard of that being mentioned as the catalyst, and - forgive my ignorance - I can't imagine why the fall of Kabul would prompt this decision. Care to elaborate as to why, and/or provide a source?
Perhaps just a coincidence (though I doubt it), but the full-screen login pop-ups on mobile became constant that weekend. Seemed like most of the videos coming out of Kabul airport that weekend were sourced off Twitter.
Somewhat perverse that it seems like the fall of Kabul was the motivation for this change.