It's also anachronistic to speak of the TOS Enterprise having a "warp core," or to refer to TOS landing parties as "away teams." A lot of Trekkers do it, though.
Well, in-universe, we don't know that the fictional characters didn't call them "Bussard collectors," since we never heard them call them anything else. So that's not really the problem. But if you're writing a historical article about artifacts created in the 1960s and 1970s, it's misleading to talk about them using terminology that wasn't applied to them until the late 1980s, unless you specifically point out that the term wasn't in use at the time. Nothing wrong with the modern interpretation, of course, but if you're chronicling the history of a thing, it's best to make the chronology clear.