There are scholarly lectures by Amber O’Hearn and lighter (but still well-documented) ones by Georgia Ede. Dr. Berry is up on the latest research, but his videos are pegged at a more popular level.
The YouTube channels I find most helpful are Low Carb Down Under, which does various events in Australia and Colorado; Ancestral Health, which does an annual symposium with heavyweight speakers; and I just discovered JumpStartMD, which has some very good presentations from a conference they organized last year (I am trying to get organized to post a thread about this conference.)
Now, none of these channels are specifically carnivore, but they do have a lot of useful information, in any case. The Dudes and Daisy Brackenhall have interviewed various people, especially Amber, on the topic of ZC/carnivore, so a little rummaging around is required, but again, will turn up highly useful information.
If you can come across a copy, The Fat of the Land is an interesting account by the Canadian-American explorer and anthropologist, Vilhjalmur Stefansson, of his travels among the Inuit in the Canadian Arctic. He and a colleague, Karsten Andersen, were put on a meat-only diet for a year, in a famous experiment run at Bellevue Hospital in New York in 1927. The papers from this experiment are available online and make fascinating reading. Granted, it was N = 2, but it supported Stefansson’s assertions about the Inuit diet and silenced critics who believed that scurvy was an inevitable result of a meat-only diet.