Some background info
Prior to my employment, two people worked in my position previously. One of them wasn't liked very much and the other wasn't very good at his job (as stated by my supervisor and other employees). They were tasked with developing a new website for the office. They never quite finished the project before leaving to go to college.
A couple months later, enter me. I'm tasked with "cleaning" up the code. It took approximately 2 minutes to realize this wasn't going to be an easy task. The code was horribly written. We're talking random tabs and spaces in places they don't belong, hundreds of lines of CSS code embedded in the HTML files instead of being put in separate stylesheets. Poor and confusing naming conventions and confusing folder structure.
I decided to back up all the contents in to a single folder and start rebuilding it from scratch. I did this for about a week so I had a presentable project (trying to keep everything as close to the original as possible) before asking my supervisor which version they liked more. They very much approved of my version after inspecting both for some time and I was now tasked with developing the new website based on my version.
We're now nearing the release of the website to the public. I've written thousands of lines of code from the ground up keeping only what was necessary from the original. I was told I could comment crediting myself as author in the files I wrote.
Today I was told that one of the previous employees would be coming back for the summer and I need to remove all the comments crediting myself as author in my code not to upset this returning employee. I don't agree with this but obviously complied anyways as I'm in no position to challenge the decision.
Should I be allowed to leave the comments crediting myself for my work?