I don't think it's a violation, but I wouldn't recommend it because at the end of the day you want people binge watching your content. That means you want as little repetition as possible. I would also cut the length down to 5 seconds or less or your audience will get sick of watching it.
Spend 90% of your time working on your intro... why?
Look at the average watch time of your videos. If your videos average 10 minutes, it is probably going to be like 3:30-4:00. Meaning the majority of the people are not even going to see your extro. Mine are almost always just a simple 20 second clip, where I have room to pu tthe subscribe button and what to watch next. Took me a whopping 2 minutes to do. My intro was a bit more complicated.
Also like @Armchair Economics Guy mentioned, if someone gets on to your vids and starts to binge, it could get annoying real quick seeing the same thing back to back.
I usually break this up. I have a 20-25 second quick intro / teaser for the EP. Then the intro and roll into the meat of the video.
I am in no way trying to grab views, but here is a good example of how I do it, if you are interested.
I had an intro and gave it up after looking at my analytics. The big drop in viewers at the beginning was when I had an intro. The big drop at the end was when I had an outro. I gave up on both! Check out the difference in percentage viewed. Most people do not want repetitive content. I know I skip over long intros, I cannot be the only one.
I now use a 5-10 second hook, then a 3 second intro (like my station ID), at the end is a 5 second outro of some cute kids yelling "thank you Tito Tim" (just something to put the end screen on). I could probably cut both, but they do not seem to hurt video performance.
Occasionally I take a few quick clips from that video and splice 'em together to start as a teaser of what's to come. And Gediphoto here was nice enough to make me a cool 5 second animated logo that I sometimes will use as well. But I don't use them all the time. I mix it up to keep things interesting. At least for me and hopefully for the audience as well.