This is good advice for all tertiary sources such as encyclopedias, which are designed to introduce readers to a topic, not to be the final point of reference. Wikipedia, like other encyclopedias, provides overviews of a topic and indicates sources of more extensive information.

The whole paragraph is kinda FUD except for this. Normal research practice is to (get ready for a shock) do research and not just copy a high-level summary of what other people have done. If your professors were saying, “don’t cite encyclopedias, which includes Wikipedia” then that’s fine. But my experience was that Wikipedia was specifically called out as being especially unreliable and that’s just nonsense.

I personally use ChatGPT like I would Wikipedia

Eesh. The value of a tertiary source is that it cites the secondary sources (which cite the primary). If you strip that out, how’s it different from “some guy told me…”? I think your professors did a bad job of teaching you about how to read sources. Maybe because they didn’t know themselves. :-(