Well dude, it's a matter of professionalism, but you go ahead and do whatever you think is best.
I'm not making any money off of this and this is more for fun, so I am just doing what I want with it. I'm not going to make another Corrupted Lands CTM map. I will be moving into different CTM maps from now on.
I'm about 20 downloads away from 500 on Corrupted Lands. I will release a picture of the spawn for my new map tomorrow. It will be called Abundant Seas. (name could change) Something I want to do in this map is make each area bigger and some more traveling too. I feel like this was really lacking in the Corrupted Lands maps.
I found out about the same name after I made the map and released it. That series is called "Corrupt Lands" while mine is called "Corrupted Lands." I know it's not much of a difference but it is one. The "Corrupt Lands" series is pretty much dead anyway as XeroThomas hasn't updated it in quite a few months. I think the name should be fine, but if I do need to change it, I will. I like the name as is right now, so I will keep it like that.
Despite it being changed, it is still the same name. ("Corrupted" is the adjective of "Corrupt"---not to mention you used the same last word.) I agree with Eeriewolf, you should change the name... in my opinion. Like Eeriewolf said again, above, if you want to look professional then you should change it. It's your map series, though...