I never paid much attention to the lights on the dash until I saw this thread. Looked down at the dash lights as I started the car leaving work today. The AT Oil Temp light stayed on for just a bit longer (less than a second) than the others and then turned off. My car was outside for +8 hours at less than 32 degrees today and I have about 1400 miles on the odo. I also let the gauges do the full "sweep" and back to rest before I actually started the car. Who knows, maybe it just takes a bit for the temp sensor to check out as normal before the light goes off.
Anyways, I looked in the owner's manual and it says if the light is on while you are driving, the CVT transmission fluid is too hot and you should pull over and idle until the light turns off. If it is flashing, then the transmission control system may not be working properly and you should contact the nearest Subaru dealer immediately. Mine does neither so I'm not going to worry about it. My CVT has been behaving normally as far as I can tell.
...also, just searched youtube. There is a video with a 2013 cvt impreza that does the same thing.
edit... also ran a check with my OBDII reader. No codes and nothing in the freeze frame.