My memory is a bit foggy, but in Sins of the Father, where Tim becomes Robin, I believe Alfred explains that Bruce keeps the Robin suit under glass in hopes that Dick would rejoin him, or something like that.
First, we see Dick's last outing as Robin is the same classic outfit he wore in Batman: The Animated Series. So he had a new outfit made just to sit there under glass? And this is ignoring the fact that a suit made with a mid-20s man in mind fits a young teenager.
Plot hole. lol