I ask Gemini health questions non stop and never see it using YouTube as a source. Quickly looking over some recent chats :
- chat 1 : 2 sources are NIH. the other isnt youtube.
- chat 2 : PNAS, PUBMED, Cochrane, Frontiers, and PUBMED again several more times.
- chat 3 : 4 random web sites ive never heard of, no youtube
- chat 4 : a few random web sites and NIH, no youtube
To clear up potential confusion, you seem to be talking about the Gemini app (https://gemini.google.com), the chat app formerly known as Bard.
The article is about AI Overviews, a feature of Google Search (the LLM-generated box that sometimes shows up above the search results).
They're powered by the same pretrained model but, in true Google style, are two otherwise unrelated products built by two completely separate orgs.
Then there's AI Mode (https://www.google.com/ai), NotebookLM and probably some others I'm forgetting right now. :)