So I just realized I have a very similar introduction to Markiplier. As pointed out to me by a fellow Redditor. I didn't see it initially, but when he put it in quotations. It does come close. So I was wondering should I keep my introduction or change it to
"Welcome back everyone, my name is Wigglenator" then all the rest.
Actually as many of the others have already stated, it is up to you, but I can tell ya my little story about the same thing and maybe it can help a little
So I started out with Let's Playing, 2-4 videos in I began to notice that my outro was very similar to Markiplier's outro, so I stopped myself immediately to see what else I could do that others wasn't using and after some time fiddeling around with the idea, I found both my newest intro and outro: "Grab yourself a hot drink, a blanket and make yourself comfortable, my name is Trinity and this is/welcome back to [game title]" and then when the video was around the end: "Thank you guys so very much for watching, do stay tuned for more. Stay cozy and have a nice day!"
As you can see if you look at it, you can point out my outro sound a little like Jacksepticeye's but I do use my own way with some extra and that sort of became what I used in all my videos.
Nevertheless, to sum it all up for you mate. Do it the way you not only feel, but also know is the right for you and then go with it from there...one thing is to have the same lines as another, it's another thing if you try to sound exactly like them in the outro/intro sequence
I hope this help a little and the best of luck on your journey on Youtube!
Stay cozy and have a nice day! - Trinity