Yes, sometimes you want to de-duplicate pieces of information by a part of the piece and preserve order. The article tldr sounded like you can only de-duplicating by first sorting with package sort if you don't have to preserve order. However as I just wanted to point out, it works if you have to preserve order just as well.
Edit: I see now that the original article meant preserving output order. And i have not clarified that i meant input order.
Edit: I see now that the original article meant preserving output order. And i have not clarified that i meant input order.