Does shifting to neutral at stoplights affect the long term health of automatic transmission engines?

It shortens the life of your transmission by shifting in and out of gear to get the longest life you would leave it in drive at all times every time you shift in and out of gear you are putting pressure on the plates when going back in gear causing wear and tear also make shure you are completely stopped when going from forward to reverse for the best tranny life

I disagree. Long periods of idling while in gear & holding the brake, such as stop lights, trains etc. generates a LOT of excess heat, which is a Trannys worst enemy. Shifting into Neutral then back into gear is not all that hard on Trannys.

I don't believe the Engine is affected in either case.