Only devices that can't run anything newer got that update. There is no choice available.
https://en.wikipedia.org/wiki/IOS_26
When iOS 27 became available, people were given a choice to upgrade to 27, or to 26.7. I know this because I upgraded my personal phone to 27, and my work phone to 26.7.
You may have missed the button, but it was there.
Apple typically continues releasing updates for n-1 iOS for a few months. After that limited window, updates are only released for the latest iOS, except for devices which are too old to run the latest iOS, which continue receiving updates on the last-compatible iOS for a couple of years.