https://esellercafe.com/ebay-sellers-may-pay-final-values-fees-off-platform-sales/
The above link has a copy of AND an assessment of the agreement change.
First, I don't think eBay can scour PayPal to try to find items that you listed on eBay but sold outside of eBay. I'm not a lawyer, but eBay and PayPal are separate, and that would absolutely be an invasion of privacy.
For me, what's important is the REQUIREMENT to REPORT sellers and buyers who meet on eBay but try to transact outside of eBay. That requirement is the teeth in the changes.
Everything else just sounds like threats. How is eBay going to know if the tank listing you cancelled ended up selling on Craigslist? All of the "Sellers are liable for final valuation fees" jargon is just scare tactics. Until you get REPORTED.
I am a "Top Rated" eBay seller. Being Top Rated gives me substantial discounts when I ship through eBay. So, I am not going to give anyone any cause to "report" me and thus jeopardize my Top Rated status. Which sucks. Buyers see what I am selling and ask me for related items all the time, and I always try to make those sales outside of eBay. Now, that is over.
If I was not Top Rated, I would say "screw you eBay." Prove that I am violating the new agreement. Then sanction me, and guess what?, when you don't allow me to sell, you don't get my listing and valuation fees. Great business model.