Hardly a loophole - Wikipedia’s greatest strength is as an aggregator of reliable information, and using Wikipedia’s sources is how people SHOULD use it. They just taught you how to use it.
Yup. My friend is a high school teacher, and he did the same thing to his class - told them not to use Wikipedia, but that Wikipedia sources were fine, and the kids did actual research.
Schools aren't with it. I was told in the 90s that cursive was the future. We had already progressed beyond word processors and they are having us learn fucking loopy letters.
Uni wasn't much better. Found myself over thirty years behind industry when I got out.
I think it might depend on the field of study and location, but schools are often a little on the conservative side. Even so "loopholes" as best practices is arguably even better.
My SO is a little scared I will push too much information on them (I have a degree in geek), so I thought more of the pedagogic value of calling something a loophole/hack/cheat etc..
Big brain move: Tell your students about this neat loophole, gets them started on actual research.
(Ideally - I'd be lying if I said I've never used a quote from Wikipedia citing the stated source without actually reading it [usually at 5 am for papers due in two hours], but more often than not Wikipedia was the signpost for the rabbit hole)