THE SHORT ANSWER
Yes, and this week put a number on both sides. Per Rich Holmes at Department of Product, Reddit's stock fell 29% on Friday, its worst day since the IPO, after it missed revenue; its CEO said Google traffic declined meaningfully and that AI Mode does not drive traffic, and Reddit will require login to view content, with 59% of daily actives not logged in, logged-in users making up 80% of monetized users, and a licensed corpus to protect. One issue later Holmes reports Akshay Kothari's survey at Notion: the top answer to how did you hear about us is an AI tool, at 25.4% of responses, with Granola's AI-attributed activations up 4,600% since January and Vercel's ChatGPT-referred signups up 10x. The referrer moved from the results page to the assistant, and the assistant sends people to the page it can read on every visit; Ahrefs, via Holmes, found at least half of 37,500 AI citations gone by day two and about 75% returning, so the page is re-read, not ranked once. A login wall serves the licence and the logged-in ad revenue and forfeits the referral. falkster.com made the other choice in September: markdown at every URL, llms.txt, agents.md, and 331 answer pages that each name a company and a number, and my own Monday scan shows the wall from the assistant's side, 73 sources read by one request each and 21 walled ones read by hand.