Yes, if people follow you, they will notice that you have a different username, but they may not notice it's you, but under your username, after changing it, it will say 'Previous Username:' then your previous username so people know that you changed it, but they won't really know unless they see that. I made a meme and submitted it announcing that I was going to change my username, so I would suggest doing that so people are aware. Write something like 'Hey, I'm changing my username from someguynamesmat to whatever you want to change your username to. Make sure you include your old username in the image since your new username will be what appears as the creator of that image so people know that it is you. Hope this helped!
