Literally no UK university student would call themselves a college student, regardless of the few UK universities that structure themselves into colleges. I, and everyone of my university friends stopped saying we were in college when we left college (at 18) and instead said we were in uni. Every uni grad I know talks about “when I was at university” and not “when I was in college”.
The article is talking about a student in the UK, it should use the correct terminology for that country and not the US specific one.
Like I said, I’m being pedantic.