I have the mods listed in my sig. My car has been dyno tuned and I have done 20 track days with the car as well as using it as a daily driver. I had a pressure sensor go out in the transmission and the warning light came on (and stayed on). I have never seen the transmission warning light blink. I would say your issue is not "normal," but I don't know if it is truly indicative of something wrong with the transmission.
Were you driving the car hard or just cruising when this happened? Did the car have any symptoms other than the blinking light? Was it the warning light in text at the bottom of the gauge cluster or the transaxle icon in the upper right corner of the gauge cluster (or both)? Is your TCM stock or do you have the Cobb AP 006 and flashed the TCM with a Cobb map? Is your car a 2012 or an earlier model year? Do you have any other lights off or going on and off on the dash (backlight to fuel gauge, temp gauge, etc.)? The answers to these questions would help to make an educated guess.