Hi. I have a 5 year old daughter and we have almost the EXACT same bedtime routine!
I see that my daughter depends on the show before bed and if we may miss it, she gets upset about it. We often threaten to take it away if she misbehaves. It seems to work.
I know what you are saying about the transition time and calming him down... it does the same for our daughter. I thought about changing it... but I think she really needs the "down time". And if the shows are apprpriate, then I don't see anything wrong with it.
At 5 years old, he should be able to understand and adjust to a change in this routine though, if you wanted to go to NO TV on weeknights. Then he may look forward to having weekend "movie nights" with the family instead.
Let me know how it goes =)