I would have missed this. Direct link for UK users to opt out of letting ebay use your data for AI training - accountsettings.ebay.co.uk/ai-preferences. Otherwise open link to User Privacy Notice in the email you have received and scroll through to the AI section.
Opt out of training generative AI models
accountsettings.ebay.co.uk
eBay users! Don't ignore today's email, even though it looks like a boring standard update to the User Privacy Notice. They want to use your data to train AI models. If you click the link over the words "the right to object", it takes you to a page with a toggle button letting you opt out.