Some time between October 8 and October 11 the format of Southwest's emails changed. I find the new format to be more attractive, but I haven't noticed any new or deleted information elements. The first name and date are at the beginning of the Subject line, which is an improvement.

The one change in my usage is that used to search my email for 23NOV18 to find all reservations for that date. The new format requires a search for 11/23/2018.