They FINALLY fixed the issue where you can now type the name of ANYONE in a group Messages thread and the group thread will show up as a suggestion.
This behavior broke with iOS 9 and finally appears to have been corrected.
Prior to iOS 9.0, the Messages app would offer group message threads as suggestions when composing a new message.
For example, if you had a group message thread with Bill, Susan, and John...you could compose a new SMS or iMessage and begin typing the first or last name of *anyone* in the group (either Bill, Susan, OR John) and the iPhone would offer the group thread as a suggestion, in addition to the individual contact info for Bill, Susan, and John.
Since iOS 9.0, the recent group message history will only display when you begin typing the name of *one* specific member of the group. For example, typing "Bill" only brings up Bill's contact info. Typing "Susan" only brings up Susan's contact info. It's only when you type "John" that John's contact info shows up, *as well* as the group thread information.
This was very annoying, as I constantly delete my message threads but still like to quickly access my message groups when composing a new SMS or iMessage.